СПОСОБ И УСТРОЙСТВО ДЛЯ ФЛУОРЕСЦЕНТНОЙ СПЕКТРОМЕТРИИ В СКВАЖИНЕ

Прибор для измерения флуоресценции пластового флюида в стволе скважины содержит камеру с окошком, сообщающимся своей одной стороной с пластовым флюидом, другой стороной с источником ультрафиолетового излучения. Источник ультрафиолетового излучения для освещения пробы флюида и приемник излучения для измерения спектров флуоресценции пробы флюида расположены со второй стороны окошка. Также предложен способ для измерения флуоресценции пластового флюида в стволе скважины. Изобретение обеспечивает упрощение устройства и способа, а также повышение их надежности. 2 н. и 19 з.п. ф-лы, 3 ил.

ВЫСОКОЭФФЕКТИВНОЕ МУЛЬТИПЛЕКСИРОВАНИЕ

System for enhancing spectrometer resolution - shifts spectrum periodically relative to detector array

A spectrum is produced dispersing optics on a detector with a row of detector elements. The spectrum is periodically displaced relative to the detector elements. Signals are generated corresp. to the displacement amounts and signal processing equipment is supplied with detector signals and displacement signals and provides a spectrum of high resolution from the dependency of the detector signals on the displacement signals. Displacement may be effected by periodically moving the detector row in its longitudinal direction, by periodically moving an inlet aperture transverse to or in the direction of the light beam axis in the detector row plane, or by periodically moving the dispersing optics. USE/ADVANTAGE - As polychromator for liquid chromatography. Covers gaps between detector elements without making elements undesirably small.

Verfahren zur Laserspektroskopie von Gasen

Ein Verfahren zur Bestimmung einer Konzentration eines Gases in einer Probe und/oder der Zusammensetzung eines Gases mittels eines Spektrometers umfasst das Messen eines Absorptionssignals des Gases als Funktion der Wellenlänge, wobei die Wellenlänge einen Wellenlängenbereich im Wesentlichen kontinuierlich durchläuft und das kontinuierliche Durchlaufen des Wellenlängenbereichs durch eine vorzugsweise harmonische Wellenlängenmodulation überlagert wird, wobei der Einfluss der Wellenlängenmodulation auf das Absorptionssignal über die Lichtquellenmodulationseigenschaften und die Nachweiseigenschaften des Spektrometers von den Geräteeigenschaften des jeweiligen Spektrometers abhängig ist, das Umwandeln des Absorptionssignals zumindest in ein erstes Derivativsignal, das Ableiten einer Gaskonzentrationsmessgröße aus dem ersten Derivativsignal, das Bestimmen der Konzentration und/oder Zusammensetzung des Gases aus zumindest der Gaskonzentrationsmessgröße und einer Kalibrationsfunktion, durch welche ...

VORRICHTUNG UND VERFAHREN ZUM HOCHAUFLÖSENDEN BOHRLOCHSPEKTROMETER

Vorrichtung und System zur Ermittlung eines Drucks, einer Temperatur und/ oder einer Teilchendichte eines Gases oder Gasgemisches

Vorrichtung (1) zur Ermittlung eines Drucks, einer Temperatur und/oder einer Teilchendichte eines Gases oder Gasgemisches (G), aufweisend • eine Laservorrichtung (3), die dazu eingerichtet ist einen Laserstrahl (5) abzugeben, • eine Messeinheit (40), die dazu eingerichtet ist, Absorptionswerte eines Gases oder Gasgemisches (G) zu messen, wobei die Laservorrichtung (3) und die Messeinheit (40) derart angeordnet sind, dass der Laserstrahl (5) zumindest einen Teil des Gases oder Gasgemisches (G) durchqueren kann und auf die Messeinheit (40) gerichtet werden kann, so dass die Absorptionswerte des Gases oder Gasgemisches (G) mittels der Messeinheit (40) messbar sind, gekennzeichnet durch • eine Analysevorrichtung (41), die dazu eingerichtet ist, den Druck, die Temperatur und/oder die Teilchendichte des Gases oder Gasgemisches (G) aus den Absorptionswerten abzuleiten.

Verfahren und Gasanalysator zur Messung der Konzentration einer Gaskomponente in einem Messgas

Zur wellenlängenabhängigen Abtastung einer Absorptionslinie einer zu messenden Gaskomponente in einem Messgas (1) wird die Wellenlänge des Lichts (4) einer wellenlängenabstimmbaren Lichtquelle (3) innerhalb periodisch aufeinanderfolgender Abtastintervalle variiert und dabei zusätzlich mit einer Frequenz (f0) moduliert. Das modulierte Licht (4) wird durch das Messgas (1) auf einen Detektor (5) geführt, dessen Messsignal (16) bei einer Oberschwingung der Frequenz demoduliert und für jedes Abtastintervall zu einem Messergebnis ausgewertet wird. Um aus Temperaturänderungen in dem Gasanalysator resultierende Driften in den Messergebnissen zu reduzieren, erfolgt in aufeinanderfolgenden Abtastintervallen die Modulation mit mindestens zwei unterschiedlichen Modulationsamplituden (K1, K2). Zur Messkalibrierung sind in einer Speichereinrichtung (21) bei unterschiedlichen bekannten Konzentrationen der Gaskomponente für die unterschiedlichen Modulationsamplituden erhaltene Messergebnisse (20(K1), 20 ...

Method and system for reduction of influence of baseline distortion in absorption spectroscopy measurements

Vibrational circular dichroism spectroscopy

A vibrational circular dichroism (VCD) spectroscopy apparatus 5 acquires a differential absorption spectrum. A dual-comb is generated by superimposing comb outputs C1, C2 from two QCL sources 10, 12 to provide a third comb interferogram C3’. The combined comb passes through a polarisation modulator 50 to output left and right circularly polarised light. Detector 30 outputs a measurement signal from the combined comb C3’ after it has passed through sample S. Controller 14 sets the frequencies of the light signals C1, C2 such that resultant beat frequencies of the combined comb are higher than the polarisation modulation frequency so that for each left and right circularly polarised light the detector measures transmission through the sample across the wavelength range of interest during each period of the polarisation modulation. A complete vibrational spectrum is acquired in each modulation of a polarization modulator, instead of only acquiring data for a single wavelength during each modulation ...

A spectroscopy sensing method and apparatus for the measurement or detection of a material

System and method for monitoring environmental effects using optical sensors

An apparatus and method for determining a physical parameter affecting an optical sensor or a number of sensors in a network. The apparatus uses a narrow linewidth source at an emission wavelength g e and an arrangement for varying the emission wavelength g e of the radiation. An analysis module with curve fitting is used to generate a fit to the response signal obtained from the optical sensor. The physical parameter is determined form the fit rather than from the response signal. The apparatus can be employed with Bragg gratings, etalons, Fabry Perot elements or other optical sensors.

Optimisation of the laser operating point in a laser absorption spectrometer

An operating value of a first laser parameter of a laser device in a laser absorption spectrometer is optimised. The wavelength of laser device emitted light is adjusted by the first or a second laser parameter. The laser absorption spectrometer 100 comprises a lightintensity detector 120 measuring the laser light intensity from the laser device 110. For each of multiple values of the first laser parameter 112: the light intensity detector measures light intensity obtained across a range of second laser parameter values 114, and an extremum in the light intensity measure and a peak position for the extremum are identified. A range of first laser parameter values is identified within the values of the first laser parameter forwhich there is a continuous trend in changes to the identified peak position with changes to the first laser parameter. The first laser parameter operating value is set to be within the identified range. The laser parameters may comprise the laser diode temperature ...

Optical apparatus for analyzing samples

An improved optical system is disclosed for rapid, accurate spectral analysis of the reflectivity or transmissivity of samples. A concave holographic diffraction grating oscillated at high speed is utilized to provide a rapid scanning of monochromatic light through a spectrum of wavelengths. The grating is positively driven at very high speed by a unique cam drive structure comprising identically shaped conjugate cams. The rapid scan by the grating enables the reduction of noise error by averaging over a large number of cycles. It also reduces the measurement time and thus prevents sample heating by excessive exposure to light energy. A filter wheel having dark segments for drift correction is rotated in the optical path and is synchronous with the grating. Source optics is employed to optimally shape the light source for particular applications. The system optics further includes a unique arrangement of lenses, including cylindrical lenses, to obtain the best light source shape which results ...

Vibrational circular dichroism spectroscopy

Hyperspectral imaging method

Spectral modulator 102 modulates broadband light from source 101 to provide a plurality of modulated spectra which illuminate sample 105. A detector, e.g. longwave infrared camera 106, collects spectral image data using a combination of bandpass sampling and non-uniform sampling. The sample is imaged by reconstructing spectral image data, perhaps recorded onto a single spectral mask. The detector may have a 3-14 micron wavelength band. A bandpass filter may be located between the light source and modulator, or modulator and detector. The modulated spectra may be calibrated using a characteristic of the bandpass sampling, and optimised using a Fourier-transform or bandpass sampling characteristic of the spectral image data. Non-uniform sampling may involve selecting variable density sampling of points so that spectral image data is sampled at less that 25% of the Nyquist-limited sampling rate. The hyperspectral image may be reconstructed from a Fourier-transform characteristic of the spectral ...

Dual-comb spectrometry

A dual-comb spectrometer (DCS) comprises two semiconductor e.g. QCL lasers 10, 12 acting as master and follower, outputting respective frequency combs C1, C2 having a frequency offset between their inter-mode beat frequencies. Although the master laser is driven nominally with a DC drive signal Idrive,1 the current nevertheless oscillates with an AC component that follows the beating of the intermode comb lines lasing in the master, which is tapped off and mixed with a reference frequency Δfrep to provide the required frequency offset, the mixed signal then being supplied to the follower laser 12. The respective frequency combs in the optical domain are thus phase-locked relative to each other in one degree of freedom, so that the electrical signals obtained by multi-heterodyning the two optical signals are frequency stabilized. Also disclosed are dual-comb spectrometers having a noise-cancelling mixer and beat-note extracting bandpass filter, and having a bandwidth compression mixer.

NOT INVASIVE DETERMINATION OF THE GLUCOSE CONTENT IN THE BODY OF A PATIENT

Reference switch architectures for noncontact sensing of substances

This relates to systems and methods for measuring a concentration and type of substance in a sample at a sampling interface. The systems can include a light source, optics, one or more modulators, a reference, a detector, and a controller. The systems and methods disclosed can be capable of accounting for drift originating from the light source, one or more optics, and the detector by sharing one or more components between different measurement light paths. Additionally, the systems can be capable of differentiating between different types of drift and eliminating erroneous measurements due to stray light with the placement of one or more modulators between the light source and the sample or reference. Furthermore, the systems can be capable of detecting the substance along various locations and depths within the sample by mapping a detector pixel and a microoptics to the location and depth in the sample.

Spectral modification through phase modulation with spatial extent

LASER SPECKLE REDUCTION AND PHOTO-THERMAL SPECKLE SPECTROSCOPY

A method of reducing laser speckle by reflecting an infrared laser off a rotating diffuser and coupling the diffused light into a multi-mode optical fiber. Also disclosed is a photo-thermal speckle spectroscopy device having an infrared laser, a visible laser, a foam, and a camera. The infrared and visible lasers are focused on the foam, which causes the visible laser to scatter. A camera records the speckle pattern, which shifts when the IR laser is tumed on. The related method of photo-thermal speckle spectroscopy is also disclosed.

A METHOD AND APPARATUS FOR A HIGH RESOLUTION DOWNHOLE SPECTROMETER

... ²²²The present invention provides a simple, robust, and versatile high-resolution ²spectrometer that is suitable for downhole use. A method and apparatus are ²provided incorporating a spinning, oscillating or stepping optical ²interference filter (109) to change the angle at which light passes through ²the filter(s) after passing through a sample (105) under analysis downhole. As ²each filter is tilted, the color or wavelength of light passed by the filter ²changes. Black plates (111) are placed between the filters to isolate each ²filter's photodiode (113). The spectrometer is suitable for use with a wire ²line formation tester. The invention is suitable for deployment in a ²monitoring while drilling environment. A high resolution spectrometer is ²provided which enables quantification of a crude oil's percentage of ²aromatics, olefins, and saturates to estimate a sample's gas oil ratio. The ²percentage of oil-based mud filtrate contamination in a crude oil sample can ²be estimated.² ...

REAL-TIME CALIBRATION FOR DOWNHOLE SPECTROMETER

An apparatus for performing real-time analysis of a subterranean formation fluid includes a light source configured to transmit at least a sample signal through a sample of the subterranean formation fluid and a reference signal, at least one photodetector configured to continuously detect the sample and reference signals, and an electronics assembly configured to compensate for drift in the detected sample signal in real-time based on the value of the detected reference signal.

DETERMINATION OF LOCATION OF BACTERIAL LOAD IN THE LUNGS

The present invention is direct to methods of determining the location of a bacterial load in the lungs of a subject.

Spectrophotometer.

METHOD AND DEVICE FOR HIGH-RESOLUTION SPECTROMETRY IN WELL

СПОСОБ И УСТРОЙСТВО ДЛЯ СПЕКТРОМЕТРИИ ВЫСОКОГО РАЗРЕШЕНИЯ В СКВАЖИНЕ

В изобретении предлагаются способ и устройство, предусматривающие использование в скважине интерференционных светофильтров (109), имеющих возможность вращения, качания и шагового поворота для изменения угла падения света (102), проходящего через эти светофильтры после прохождения через анализируемую пробу (105). При наклоне каждого светофильтра цвет или длина волны света, проходящего через этот светофильтр, изменяется. Для изоляции фотодиода каждого светофильтра между светофильтрами расположены черные пластины-экраны. Предлагаемый спектрометр пригоден для использования с кабельным опробователем пластов для проведения дополнительного анализа и контроля чистоты проб. Настоящее изобретение также применимо в составе оборудования для получения скважинной информации в процессе бурения. Предлагаемое устройство для спектрометрии высокого разрешения позволяет определять процентное содержание в нефти ароматических углеводородов, олефинов и предельных углеводородов с целью определения соотношения ...

AUTOMATIC WAVELENGTH TRACKING SYSTEM

A METHOD FOR DETERMINING THE REPORT/RATIO OF THE CONCENTRATIONS OF TWO SUBSTANCES

Method for stabilizing the wavelength in a laser spectrometer system

A method for stabilizing the wavelength in a laser spectrometer system, including: (a) performance of an initial scanning, inlcuding a current to a diode laser, where the current value is gradually increased from the minimum current to a maximum value to cover a predetermined overall value, where the minimum and the maximum are selected thus to keep the absorption characteristics of the specimen in the minimum and maximum scanning range; (b) in last scanning, the applied current value being analyzed of signal by the detector to have the current value in last scanning have its corresponding position be determined; (c) determination of a corresponding absorption signal to the absorption characteristics; (d) selection of calculation of density of the speicmen pending for test; (e) resetting last scanning current value to define a new current scanning, for theabsorption characteristics of the new current scanning match the last scanning; (f) performance of an additional scanning; and (g) repeating ...

LIGHT SOURCE APPARATUS PROVIDED WITH MODULATING FUNCTION AND METHOD FOR DRIVING SAME

A light source apparatus provided with a modulating function has a wavelength converting module (75), which has a structure wherein a nonlinearity constant is periodically modulated and is made of a nonlinear optical material. The light source apparatus outputs a difference frequency or a sum frequency, which are generated by multiplexing excitation lights having different wavelengths from semiconductor laser light sources (71, 72) by a WDM coupler (74) and by permitting the light to enter a light guide. The light source apparatus is characterized in that the semiconductor laser light source (72) houses a diffraction grating, and the semiconductor laser light source (71) includes a means for modulating an output light emitted from the semiconductor laser, is externally connected with an FBG (73) having a reflection band narrower than a resonance wavelength decided by an element length of the semiconductor, and inputs an modulated output to the FBG (73).

METHOD FOR SPECTROSCOPY AND IMAGING AND EQUIPMENT FOR CARRYING OUT SAID METHOD

A method and an apparatus for carrying out a chemical-physical analysis, such as a spectroscopic analysis, an absorption analysis, a scattering analysis, etc. on one or more regions of a sample (11 ), provides prearranging a source (1 ) of a first electromagnetic radiation comprising a plurality of components with respective wavelength, prearranging a plurality of sites (9) distributed on a determined surface to emit the first radiation, arranging such surface facing a corresponding region of a sample (11 ) such that the whole surface thereof is attained by the first radiation, emitting the first radiation on the sample (11) thus causing the emission of a second radiation by the sample (11 ), which is analysed to associate an intensity of the second radiation to each region and wavelength. For each of the wavelength of the first radiation, a wavelength code is selected by which respective components of the first radiation are coded; the coded components are joined together to form the first ...

Chamber effluent monitoring system and semiconductor processing system comprising absorption spectroscopy measurement system, and methods of use

Provided is a novel chamber effluent monitoring system. The system comprises a chamber having an exhaust line connected thereto. The exhaust line includes a sample region, wherein substantially all of a chamber effluent also passes through the sample region. The system further comprises an absorption spectroscopy measurement system for detecting a gas phase molecular species. The measurement system comprises a light source and a main detector in optical communication with the sample region through one or more light transmissive window. The light source directs a light beam into the sample region through one of the one or more light transmissive window. The light beam passes through the sample region and exits the sample region through one of the one or more light transmissive window. The main detector responds to the light beam exiting the sample region. The system allows for in situ measurement of molecular gas impurities in a chamber effluent, and in particular, in the effluent from a ...

Spectroscopic systems and methods

The present invention relates to spectroscopic methods and systems for collecting electromagnetic radiation from an object using a continuously-spinning wavelength-selecting (CSWS) device, e.g., an interference filter(s)?? or grating. One embodiment of the invention provides a spectroscopic system for collecting electromagnetic radiation from a target. The spectroscopic system has at least one beam of electromagnetic radiation that interacts with the target. The system includes a continuously spinning wavelength-selecting (CSWS) device, e.g., a continuously spinning interference filter/grating driven by a DC motor, in the path of the at least one beam. The device filters the radiation with regard to wavelength to produce filtered radiation. The system further includes at least one detector in the path of the at least one beam for detecting the filtered radiation.

High efficiency multiplexing

In a method for measuring radiation, the radiation is temporally and/or spatially separated by a modulator to direct at least N different combinations of radiation incident on each region into at least two and fewer than N distinct directions. The total intensity of radiation in each direction is measured with a detector for each modulator configuration and the detector outputs are analyzed statistically to obtain information relating to the spectral properties of the radiation. In this way substantially all of the energy received at the entrance aperture of a measurement device is encoded into multiple outputs and the multiplexed output is received by a small number of detectors.

Method and apparatus for two-dimensional spectroscopy

Preferred embodiments of the invention provide for methods and systems of 2D spectroscopy using ultrafast, first light and second light beams and a CCD array detector. A cylindrically-focused second light beam interrogates a target that is optically interactive with a frequency-dispersed excitation (first light) pulse, whereupon the second light beam is frequency-dispersed at right angle orientation to its line of focus, so that the horizontal dimension encodes the spatial location of the second light pulse and the first light frequency, while the vertical dimension encodes the second light frequency. Differential spectra of the first and second light pulses result in a 2D frequency-frequency surface equivalent to double-resonance spectroscopy. Because the first light frequency is spatially encoded in the sample, an entire surface can be acquired in a single interaction of the first and second light pulses.

Method of determining the concentration of a gas component and spectrometer therefor

The invention relates to a method and to a spectrometer for determining the concentration of a gas component, wherein a light source of the spectrometer is operated as in wavelength modulation spectroscopy (WMS). Thus a determination of the concentration can also take place in accordance with WMS and the measured data can, however, additionally be processed, namely a sorting takes place on the time axis, such that the concentration can be determined using the methods of direct absorption spectroscopy (DAS).

Optical assembly, apparatus and method for coherent two- or more-dimensional optical spectroscopy

Disclosed herein is a an optical assembly 12 for use in coherent two- or more-dimensional optical spectroscopy. The optical assembly 12 comprises splitting means for splitting a base light pulse into a first, a second, a third and a fourth light pulse and delay means 24, 34 for varying the arrival times of the first to fourth light pulses at a sample location 44 with respect to each other. The splitting means comprise a cross-grating 20 configured to simultaneously split the base pulse into said first to fourth light pulses, a first reflector 22 arranged to receive the first to fourth light pulses emerging from the cross-grating 20 and to reflect the same in parallel to each other, a second reflector 42 arranged to receive the first to fourth light pulses after having passed the delay means and focus the same at the sample location, wherein the delay means are arranged downstream of the first reflector and upstream of the second reflector with regard to the direction of propagation of the ...

Photometric apparatus with multi-wavelength excitation

СПОСОБ И УСТРОЙСТВО ДЛЯ ФЛУОРЕСЦЕНТНОЙ СПЕКТРОМЕТРИИ В СКВАЖИНЕ

... 1. Скважинное устройство для флуоресцентной спектрометрии, содержащее зонд, перемещаемый по стволу скважины; камеру для размещения взятой из пласта пробы флюида во время исследования указанной пробы, содержащую первое окошко, пропускающее излучение к находящейся в камере пробе, и второе окошко, пропускающее излучение из находящейся в камере пробы; источник ультрафиолетового (УФ) излучения для облучения находящейся в камере пробы; установочное устройство для фиксации источника УФ-излучения; оптически прозрачный УФ-соединитель, расположенный между одной внешней поверхностью вместилища для флюида и установочным устройством в соприкосновении с ними; фотоприемник для измерения спектров флуоресценции пробы; модель флуоресценции для определения процентного содержания в пробе ароматических углеводородов, олефинов, предельных углеводородов и загрязняющих примесей на основании соотношения результатов измерений в двух или более флуоресцентных каналах; и процессор для определения свойств нефти для ...

Скоростной спектроанализатор

Vorrichtung und Verfahren zur kohärenten mehr-dimensionalen optischen Spektroskopie

Gezeigt werden eine Vorrichtung (10) und ein Verfahren zur kohärenten, mehrdimensionalen optischen Spektroskopie mit Mitteln (14, 26) zum Aufspalten eines Basislichtpulses (12) in mindestens einen ersten bis vierten Lichtpuls, wobei der erste, der zweite und der dritte Lichtpuls zur Wechselwirkung mit einer Probe (40) geeignet sind, um ein Signal mindestens dritter Ordnung zu erzeugen, einer Fokussiereinrichtung (36) zum Fokussieren des ersten bis vierten Lichtpulses an einem Probenort, und Verzögerungsmitteln (18, 28), die geeignet sind, die Zeitpunkte des Eintreffens des ersten bis vierten Lichtpulses am Probenort relativ zueinander zu variieren. Ferner umfasst die Vorrichtung (10) eine Detektionseinrichtung zum Detektieren eines Interferenzsignals aus dem Signal mindestens dritter Ordnung und dem vierten Puls. Die Mittel zum Aufspalten des Basislichtpulses (12) sind durch nicht diffraktive Mittel (14, 26) gebildet. Die Lichtpulse werden zumindest abschnittsweise derart paarweise geführt ...

Verfahren und Vorrichtung zur Überwachung des Oberflächenzustandes von Bauteilen

Die Erfindung betrifft ein Verfahren und eine Vorrichtung zur Überwachung des Oberflächenzustandes von Bauteilen, deren Oberfläche mehrere Schichten umfasst, um damit äußere Schäden unterschiedlicher Ausprägung örtliche differenziert erkennen zu können. Dabei umfasst das Verfahren die Verfahrensschritte, des zumindest abschnittsweisen, breit- oder schmalbandigen Beleuchtens der Oberfläche zumindest eines Bauteils durch elektromagnetische Strahlung mit einer Beleuchtungseinheit 9, des Erfassens der von dem Bauteil reflektierten elektromagnetischen Strahlung mit einer Aufnahmeeinheit 10 sowie einer frequenzselektiven Auswertung der erfassten Aufnahme mit einer Auswerteeinheit 24, so dass anhand des frequenzabhängigen Absorptionsverhaltens oder Fluoreszenzverhaltens 15, 16, 17 zumindest einer Schicht der Oberfläche eines Bauteils eine Schädigung dieser ermittelbar ist.

Automatische Kontrolle der Hydrophilie einer festen Oberfläche mit Infrarotspektroskopie

Verfahren zur Kontrolle der Hydrophilie einer festen Oberfläche nach einer hydrophilierenden Behandlung, wobei man die Oberfläche mit Wasser benetzt, mit Infrarotstrahlung bestrahlt, die Intensität der von der Oberfläche zurückgestrahlten Infrarotstrahlung bei einer vorgegebenen Wellenlänge oder bei mehreren vorgegebenen Wellenlängen mißt und aus der gemessenen Intensität die mittlere Belegung der Oberfläche mit Wasser bestimmt, dadurch gekennzeichnet, daß die Bestimmung der Hydrophilie der Oberfläche programmgesteuert automatisch abläuft und das Ergebnis der Bestimmung lokal oder an einem entfernten Ort ausgegeben oder zur weiteren Verarbeitung auf einem Datenträger gespeichert wird und/oder je nach Ergebnis der Bestimmung lokal oder an einem entfernten Ort ein Warnsignal erzeugt wird und/oder in dem Fall, daß die hydrophilierende Behandlung der Oberfläche in deren Reinigung besteht, automatisch eine Überprüfung der Zusammensetzung der zur Reinigung der Oberflächen verwendeten Reinigerlösung ...

System and method for monitoring environmental effects using optical sensors

Wavelength-dependent light intensity modulation in multivariate optical computing devices using polarizers

Multivariate optical computing using polarizers to modulate the intensity of sample-interacted light. The polarizer(s), along with other device components, produce a spectroscopic intensity profile that mimics the regression vector that corresponds to the sample characteristic(s) of interest.

OPTICAL LONG-PATH MONITORING APPARATUS

IMPROVEMENTS IN OR RELATING TO OPTICAL GAS DETECTORS

Scattered light integrating collector

Logging system and method for in-situ fluids sensing through optical fiber with attenuation compensation

Gas measuring arrangement having an open optical path of measurement

A gas measuring arrangement having an open optical path of measurement. The measuring arrangement 1, which has an open path of measurement 7, is formed by a measuring unit 5 which has an arrangement of lenses 10, 12, 19, 24, a phase mask 22, an obliquely positioned mirror 16 and a reflecting mirror 3 which is situated outside the measuring unit 1, at the end of the open path of measurement 7. The coupling-out of light to a detector 26 is performed by a phase mask 22 and a mirror 16, the phase mask 22 expanding a light intensity spot and the light intensity doughnut being coupled out to a detector 26 by an obliquely positioned mirror 16. The phase mask 22 may be a combined component with a lens or a spiral phase mask. The reflecting mirror 3 may be arranged on a housing part (54, Fig 4) with a cover (56, Fig 4) to protect an inside path of measurement (57, Fig 4) from the effects of weather.

Dual-comb spectroscopy

Terahertz frequency domain spectrometer with phase modulation of source laser beam

SPECTROMETER SYSTEM

... 1393385 Photo-electric spectrometers FLORIDA BOARD OF REGENTS STATE OF 13 June 1972 27694/72 Heading G1A In a photo-electric spectrometer, the entrance slit 13 of the mono-chromator 14 is arranged to be oscillated at constant frequency so as to modulate the wavelength of the input beam sinusoidally. As shown, light from source 11 and mirror 12 is passed through the oscillating slit, constructional details of which are as shown in Fig. 2, with apertured plate 35 being carried by rod 42 which is driven back and forth by elongated magnet 43 moving inside solenoids 44, 45 against the pressure of leaf-springs 39. The circuit for the slit drive is illustrated in Fig. 3 (not shown). The grating mono-chromator 14 output passes through test cell 16, in which e.g. polluted gases may be contained, to a photo-multiplier 18. The detector output is amplified at 22 and the D.C. component applied direct to recorder 21, while the A.C. component is filtered at 25, amplified at 26, and detected by chopper ...

A SPECTROSCOPY SENSING METHOD AND APPARATUS FOR THE MEASUREMENT OR DETECTION OF A MATERIAL

Gas flux measuring device

Non-invasive determination of glucose concentration in body of patient

Optical absorbance measurements with self-calibration and extended dynamic range

Detector data representative of an intensity of light that impinges on a detector after being emitted from a light source and passing through a gas over a path length can be analyzed using a first analysis method to obtain a first calculation of an analyte concentration in the volume of gas and a second analysis method to obtain a second calculation of the analyte concentration. The second calculation can be promoted as the analyte concentration upon determining that the analyte concentration is out of a first target range for the first analysis method.

Optical absorbance measurements with self-calibration and extended dynamic range

Detector data representative of an intensity of light that impinges on a detector after being emitted from a light source and passing through a gas over a path length can be analyzed using a first analysis method to obtain a first calculation of an analyte concentration in the volume of gas and a second analysis method to obtain a second calculation of the analyte concentration. The second calculation can be promoted as the analyte concentration upon determining that the analyte concentration is out of a first target range for the first analysis method.

Cavity enhanced spectroscopy using off-axis paths

Methods and apparatuses (500) of generating and processing a real-time time-domain cavity ringdown spectroscopy (CRDS) signal from absorbing species in an optical detection system having an optical ringdown cavity (200) using off-axis paths (230) are provided. At least one modulated light signal (570) is generated using one or more light sources (520), each modulated at specified modulation frequency. Each modulated signal has harmonic frequency components and is input off-axis (230) relative to the cavity's optical axis (220). The cavity contains mirrors (210, 212, 214; 310; 410; 510, 512, 514) arranged in a predetermined configuration. The optical axis (220) is defined by a path passing through centers of mirrors (210, 212, 214; 310; 410; 510, 512, 514). The modulated light signal (570) is resonated off axis (230) without astigmatic optical elements to produce CRDS signal and passes at least twice through cavity and across the mirrors (210, 212, 214; 310; 410; 510, 512, 814) without interfering ...

Multiplexed spectroscopic absorbance from CRDS wave forms

Methods and optical detection systems (200, 300, 800, 900) for generating and processing a real-time time-domain cavity ringdown spectroscopy (CRDS) signal (831, 931) from an absorbing species in an optical detection system (200, 300, 800, 900) having an optical ringdown cavity (200, 300) are disclosed. The optical ringdown cavity (200, 300) is adapted for accepting a sample of an absorbing species. One or more modulated light signals (241,243,245,341) are generated using one or more light sources (240, 242, 244, 340). The light source(s) (240, 242, 244, 340) is pulsed at a specified pulse rate(s). The modulated light signal(s) (241,243,245, 341) is resonated using the optical ringdown cavity (200, 300) comprising a plurality of mirrors(220, 230), or sets of mirrors (320, 330), to produce the CRDS signal (831, 931). The reflectivity of the mirrors (220, 230), or sets of mirrors (320, 330), is dependent upon the pulse rate of the modulated light signals (241,243,245,341). Different beamlines ...

METHOD FOR CALIBRATING SPECTROPHOTOMETRIC APPARATUS

Described is a method for determining the concentration of an analyte in a future sample that is measured on a second apparatus. This method involves incorporating, in a second apparatus, at least one primary calibration algorithm that is developed using absorbances of samples from a primary calibration set. The absorbances, which are optionally pre-processed prior to primary calibration algorithm development, are obtained from one or more first apparatus. The absorbance values of the future sample are measured on the second apparatus at one or more than one wavelength from a standard set of wavelengths, and a concentration of the analyte in the future sample is calculated by applying the Primary Calibration Algorithm to the optionally pre-processed absorbance of the future sample obtained from the second apparatus.

OXYGEN ANALYSIS EMPLOYING ABSORPTION SPECTROSCOPY

IN SITU METHODS FOR MEASURING THE RELEASE OF A SUBSTANCE FROM A DOSAGE FORM

A detection system used for continuously measuring the release of a drug from a pharmaceutical dosage form comprising a singular dissolution vessel or multiple dissolution vessels (60) containing a dissolution medium and a measuring device (50) for detecting the amount of drug released at a given time is provided.

AUTOMATIC MONOCHROMATOR-TESTING SYSTEM

HIGH EFFICIENCY MULTIPLEXING

In a method for measuring radiation, the radiation is temporally and/or spatially separated by a modulator to direct at least N different combinations of radiation incident on each region into at least two and fewer than N distinct directions. The total intensity of radiation in each direction is measured with a detector for each modulator configuration and the detector outputs are analyzed statistically to obtain information relating to the spectral properties of the radiation. In this way substantially all of the energy received at the entrance aperture of a measurement device is encoded into multiple outputs and the multiplexed output is received by a small number of detectors.

REAL-TIME CALIBRATION FOR DOWNHOLE SPECTROMETER

An apparatus for performing real-time analysis of a subterranean formation fluid includes a light source configured to transmit at least a sample signal through a sample of the subterranean formation fluid and a reference signal, at least one photodetector configured to continuously detect the sample and reference signals, and an electronics assembly configured to compensate for drift in the detected sample signal in real-time based on the value of the detected reference signal.

METHODS OF DIAGNOSING PROLIFERATIVE DISORDERS

The present invention relates to methods of diagnosing and/or prognosing proliferative disorders, especially brain cancers (e.g. gliomas). In particular, the present invention provides a means to conveniently detect malignant tumours merely by assaying or analysing blood (particularly blood serum). Cytokines and/or angiogenesis factors in blood serum have been found to be surprisingly powerful at indicating the presence of brain cancers in a subject. Moreover, spectroscopic analysis, especially ATR-FTIR analysis, of a blood sample has been demonstrated to be surprisingly effective at producing a signature that can be correlated with the presence, extent, severity, or aggressiveness of malignant tumours in a subject.

PULSE WIDTH MODULATION OF CONTINUUM SOURCES FOR DETERMINATION OF CHEMICAL COMPOSITION

A light source and a method for its use in an optical sensor are provided, the light source including a resistively heated element. The light source includes a power circuit configured to provide a pulse width modulated voltage to the resistively heated element, the pulse width modulated voltage including: a duty cycle with a first voltage; and a pulse period including a period with a second voltage, wherein: the duty cycle, the first voltage, and the pulse period are selected so that the resistively heated element is heated to a first temperature; and the first temperature is selected to emit black body radiation in a continuum spectral range. Also provided is an optical sensor for determining a chemical composition including a light source as above.

SPECTRAL MODIFICATION THROUGH PHASE MODULATION WITH SPATIAL EXTENT

An optical pulse propagating in an optical guide of am dectro-optic medium (104) interacts with a coplanar RF traveling wave to shift the optical wavelength The RF phase is resynchronized to the optical pulse with spatial periodicity to provide a desired phase relationship between RF and optical radiation. A unidirectional incremental wavelength shifter (104) comprises a frequency multiplexer for soliton communication and a symmetrical sideband modulator of this type (106) varies the spectral width of the probe the illumination in an atomic absorption spectrometer probe beam.

Method for stabilizing wavelength in laser spectrometer system

PHOTOMETER HAS SIMPLE BEAM

REAL-TIME CALIBRATION FOR DOWNHOLE SPECTROMETER

An apparatus for performing real-time analysis of a subterranean formation fluid includes a light source configured to transmit at least a sample signal through a sample of the subterranean formation fluid and a reference signal, at least one photodetector configured to continuously detect the sample and reference signals, and an electronics assembly configured to compensate for drift in the detected sample signal in real-time based on the value of the detected reference signal.

VERY LOW COST NARROW BAND INFRARED SENSOR

An optical sensor for detecting a chemical in a sample region includes an emitter for producing light, and for directing the light through the sample region. The sensor also includes a detector for receiving the light after the light passes through the sample region, and for producing a signal corresponding to the light the detector receives. The sensor further includes a thermo-optic filter disposed between the emitter and the detector. The optical filter has a tunable passband for selectively filtering the light from the emitter. The passband of the optical filter is tunable by varying a temperature of the optical filter. The sensor also includes a controller for controlling the passband of the optical filter and for receiving the detection signal from the detector. The controller modulates the passband of the optical filter and analyzes the detection signal to determine whether an absorption peak of the chemical is present.

FOURIER TRANSFORM SPECTROMETER APPARATUS MULTI-ELEMENT MEMS

A Fourier Transform (FT) spectrometer apparatus uses multi-element MEMS (Micro-Electro-Mechanical-Systems) or D-MEMS (Diffractive Micro-Electro-Mechanical-Systems) devices. A polychromatic light source is first diffracted or refracted by a dispersive component such as a grating or prism. The dispersed beam is intersected by a multi-element MEMS apparatus. The MEMS apparatus encodes each spectral component thereof with different time varying modulation through corresponding MEMS element. The light radiation is then spectrally recombined as a single beam. The beam is further split into to a reference beam and a probe beam. The probe light is directed to a sample and then the transmitted or reflected light is collected. Both the reference beam and probe beam are detected by a photo-detector. The detected time varying signal is analyzed by Fourier transformation to resolve the spectral components of the sample under measurement.

STIMULATED RAMAN SCATTERING DETECTION APPARATUS

The stimulated Raman scattering detection apparatus includes first and second light pulse generators (1, 2) respectively generating first and second light pulses with first and second pulse periods, an optical system combining the first and second light pulses and focusing the combined light pulses onto a sample, and a detector (10) detecting the second light pulses intensity-modulated by stimulated Raman scattering generated by focusing of the combined light pulses onto the sample. The second light pulse generator divides each raw light pulse emitted with the second pulse period into two light pulses, delays one of the two light pulse with respect to the other thereof and combines the one light pulse divided from one raw light pulse and delayed, with the other light pulse divided from another raw light pulse emitted after the one raw light pulse, to generate the second light pulse.

REAL-TIME CALIBRATION FOR DOWNHOLE SPECTROMETER

An apparatus for performing real-time analysis of a subterranean formation fluid includes a light source configured to transmit at least a sample signal through a sample of the subterranean formation fluid and a reference signal, at least one photodetector configured to continuously detect the sample and reference signals, and an electronics assembly configured to compensate for drift in the detected sample signal in real-time based on the value of the detected reference signal.

Two-beam interferometer for fourier transform spectroscopy with double pivot scanning mechanism

A two-beam interferometer for Fourier Transform spectroscopy has a double pivot scanning mechanism. The interferometer has two rigid pendulums that are each rotatable to swing around an associated one of distinct axes of rotation. A linkage links the two rigid pendulums to each other and constrains their rotation relative to each other. The interferometer has bearings, which may be flexure bearings, for rotatably mounting the two pendulums to swing around an associated one of the distinct axes of rotation and a first and a second bearing linking the linkage to an associated one of the pendulums. The two rigid pendulums, the linkage and the bearings can be a monolithic structure.

HYDROGEN GAS SENSOR AND METHOD FOR MEASUREMENT OF HYDROGEN UNDER AMBIENT AND ELEVATED PRESSURE

Gas sensor capable for in-situ non-contact optical measurements of hydrogen gas (H2) and method for measuring hydrogen gas under ambient and elevated pressures without the need for cells with extremely long optical path length. The gas sensor can be configured for dual gas measurements such as H2 and CO2. 1500600650600200021002100270021005002500650251026002510260027002700500550270027002700. Gas analyzer based on tuneable laser spectroscopy for measurement of concentration of Hydrogen gas , H2 , in a target gas () comprising a gas matrix possibly comprising interfering gases , the analyzer comprising a transmitter part () and a receiver part () , the transmitter part () comprising a tunable laser () arranged for emitting laser light in the form of a laser beam () , the laser beam () following an optical path , a processing unit () performing housekeeping including means for laser tuning and laser modulation , wavelength of the laser light being tuned across an absorption line of the at least one gas component to be measured , the laser beam () passing through the target gas () and onto a light sensitive detector () comprised by the receiver part () , the light sensitive detector generating an absorption signal () possibly comprising an absorption signal contribution from the gas component to be measured and from the interfering gases , a digitization unit () digitizing the absorption signal () , the digitized absorption signal from the digitization unit () being inputted to the processing unit () , the processing unit () performing calculation of the measured concentration of gas component to be measured in the target gas () based on the digitized absorption signal , the analyzer characterised by the wavelength of the laser light being tuned across an H2 absorption line near 2122 nm , the gas analyzer further comprising a sealed reference gas cell () comprising an other gas than H2 with at least one absorption line spectrally adjacent to the absorption line of H2 , ...

Envelope functions for modulation spectroscopy

A spectrometer and spectrometry method comprising modulating a light source with a carrier waveform multiplied by an envelope function, directing light from the light source through a sample region and to a photodetector, and demodulating current from the photodetector at a reference frequency. Also a method for computing a modulation waveform comprising specifying a target detection efficiency in a Fourier space, computing a response of a waveform that comprises a carrier wave multiplied by an envelope function, and modifying the envelope function using nonlinear optimization means to minimize a difference between the computed response and a predetermined target gain spectrum.

MULTIPLE LASER OPTICAL FEEDBACK ASSISTED CAVITY ENHANCED ABSORPTION SPECTROSCOPY SYSTEMS AND METHODS

Systems and methods for detecting trace gases utilize a resonance optical cavity and one, two or more coherent light sources coupled to the cavity through one or more cavity coupling mirrors, whereby two or more optical cavities may share the same gas volume.

Dual-comb spectroscopy

A dual-comb spectrometer comprising two lasers outputting respective frequency combs having a frequency offset between their intermode beat frequencies. One laser acts as a master and the other as a follower. Although the master laser is driven nominally with a DC drive signal, the current on its drive input line nevertheless oscillates with an AC component that follows the beating of the intermode comb lines lasing in the driven master laser. This effect is exploited by tapping off this AC component and mixing it with a reference frequency to provide the required frequency offset, the mixed signal then being supplied to the follower laser as the AC component of its drive signal. The respective frequency combs in the optical domain are thus phase-locked relative to each other in one degree of freedom, so that the electrical signals obtained by multi-heterodyning the two optical signals are frequency stabilized.

ACTIVE REMOTE SENSING USING A SPECTRAL LOCK-IN TECHNIQUE

MULTIPLE LASER OPTICAL FEEDBACK ASSISTED CAVITY ENHANCED ABSORPTION SPECTOSCOPY SYSTEMS AND METHODS

METHOD FOR STABILIZING WAVELENGTH OF LASER SPECTROSCOPE SYSTEM

PROBLEM TO BE SOLVED: To provide a method for stabilizing the wavelength of a laser spectroscope that is useful for spectrophotometry. SOLUTION: Initial scanning is made by supplying a current signal or a voltage signal to a laser. The current signal value or the voltage signal value are increased with a constant increment over the total number of signal values determined in advance from a minimum signal value to a maximum signal value. The minimum signal value and the maximum signal value are selected so that absorption characteristics of a seed to be measured enter a scanning range whose boundary is determined by them (a). The relative position of absorption characteristics for the supply signal value of the previous scanning is measured by analyzing the output of a detector corresponding to the signal value of previous scanning (b). An absorption value corresponding to the absorption characteristics is measured (c). The concentration of the seed to be measured is calculated (d). A signal ...

СПОСОБ И СИСТЕМА ДЛЯ ОЦЕНКИ ОБРАЗЦОВ

Изобретение относится к области интерференционной спектроскопии, предназначено для оценки, по меньшей мере, одного химического и/или физического свойства образца или пробы и предлагает альтернативную стратегию корреляции интерференционной информации с химическими и/или физическими свойствами образца, а также способ стандартизации интерферометра. Способ и система оценки используют средство модуляции, которое содержит интерферометр с разностью оптических путей в диапазоне от 10 мкм до 10000 мкм, которая получается за счет перемещения, по меньшей мере, одного оптического компонента интерферометра, используя твердотельный возбудитель. Изобретение позволяет упростить оценку без существенного снижения ее статистического качества. 9 н. и 125 з.п. ф-лы, 7 ил.

Absorption spectroscopic determination of specific gas components in mixtures, using frequency modulated laser, particularly in medical applications, e.g. monitoring of patient's oxygen levels during anaesthesia

The method involves irradiating a gas sample from a stable, single mode laser diode, whose output wavelength is continuously modulated by varying the control current. The intensity of the laser beam after transmission through the gas sample is measured by a detector for the components corresponding to the direct current component and the doubled sinusoidal frequency of the second harmonic. The laser control current is varied by imposing a predetermined sinusoidal alternating current on a direct current energy supply, so that a laser wavelength is produced which is in the same region as the absorption line for the selected gas species. The concentration of the selected gas species is calculated from the absorption line width of the minimum and maximum of the second harmonic. Preferably, the laser diode is a vertical cavity surface emitting laser diode. The second harmonic for the detector signal is determined using a lock in amplifier. An Independent claim is included for a device for implementing ...

Derivativ-Spektrometer

Spektrale Änderungen durch Phasenmodulation mit räumlicher Erstreckung

Verfahren zur Detektion von gasförmigen, molekularen Spezien in den Kammerabgasen einer Halbleiterprozesskammer, und damit ausgerüstetes Halbleiterverarbeitungssystem

ZWEISTRAHL-PHOTOMETER MIT INTERFERENZFILTER

Gas concentration measurement

A gas or vapour can be detected and measured using a source 14 arranged to send a beam 15 of radiation through a sample chamber 12 to a detector 18. The beam 15 is also passed through a narrow bandwidth multi-layer filter 16, and the angle of incidence to the filter 16 is oscillated so that the transmitted wavelength varies in an oscillatory fashion over a range in which the absorption of the gas varies. The resulting signal variations from the detector 18 at the frequency of the filter oscillation, or at an integral multiple of that frequency, enable the gas to be detected and measured. ...

Logging system and method for in-situ fluids sensing through optical fiber with attenuation compensation

Method and system for reduction of influence of baseline distortion in absorption spectroscopy measurements

A method and system for reducing the effect of distortions on the baseline signal in an absorption spectroscopy system 100 used for measurement of chemical species in a medium 120, includes controlling a source of radiation 105 to emit a wavelength modulated beam, detecting 130 the modulated beam after transmission through the medium, processing 140 the detected beam to obtain a signal indicative of the absorption effects of one or more measurands, wherein the processing includes correlating or convolving the indicative signal with a kernel function selective for a predicted signal feature. The shape of the kernel function is chosen to reduce the influence of the baseline distortions on the processed measurand determination and may be Lorentzian, Gaussian, Voight, or sinusoidal, and may also enhance the absorption signal. The system may be a tunable diode laser spectroscopy (TDLS) system.

Spectrometer and method

A chirped laser dispersion spectrometer (CLaDS) comprises two tunable lasers 20, 25 each with a bias current supply 45, a chirp signal source 46 to provide a matching chirp pattern, a beam splitter 50 to produce a single beam from the two first and second tunable lasers and active-phase locking means to render the two beams phase coherent and to produce a radio frequency-carrier signal capable of programmable phase modulation by means of an optical beat signal. Also disclosed is a method for generating at least two optical frequency signals for use in a frequency modulation spectroscopy (FMS) process for the detection and/or measurement of molecular species in a gas mixture. The apparatus is suitable for use in Zeeman, Faraday or Stark Effect spectroscopy. The bias current supply 45 may be provided by a common bias current supply. The phase locking technique may be negative electronic feedback or optical injection.

Optimisation of the laser operating point in a laser absorption spectrometer

INFRA RED FILTER

Cavity enhanced laser based isotopic gas analyzer

Systems and methods for measuring the isotope ratio of one or more trace gases and/or components of gas mixtures such as different gas species present in a gas mixture. The system includes a resonant optical cavity having two or more mirrors and containing a gas, the cavity having a free spectral range that equals the difference between frequencies of two measured absorption lines of different gas species in the gas, or of two different isotopes, divided onto an integer number. The system includes a continuous-wave tunable laser optically coupled with the resonant optical cavity and a detector system for measuring an absorption of laser light by the gas in the cavity. The detector system includes a photo-detector to measure an intensity of the intra-cavity light, or both a photo-acoustic sensor to measure photo-acoustic waves generated in the cavity and a photo-detector to measure an intensity of the intra-cavity light.

Time-synchronized tdlas measurements of pressure and temperature in a gas turbine engine

A method of absorption spectroscopy to determine a rapidly variable gas parameter. The method includes transmitting light from a synchronization light source to a synchronization detector. The transmitted light is periodically interrupted by a moving mechanical part between the synchronization light source and synchronization detector. The output from the synchronization detector is used to generate a repeating time signal having variable phase delay. This signal is used to control the timing of laser spectroscopy wavelength scans. Multiple spectroscopic scans may be repeated at multiple selected time signal phase delay and the results averaged for each phase. Apparatus for implementing the above methods are also disclosed.

SPECTROSCOPIC MEASUREMENT DEVICE AND SPECTROSCOPIC MEASUREMENT METHOD

A spectroscopic measurement device includes a variable wavelength interference filter provided with a first reflecting film, a second reflecting film, and an electrostatic actuator for changing a gap amount of a gap between the first reflecting film and the second reflecting film, a detection section adapted to detect the light intensity of the light taken out by the variable wavelength interference filter, a voltage setting section and a voltage control section for applying an analog voltage varying continuously to the electrostatic actuator, a voltage monitoring section for monitoring the voltage applied to the electrostatic actuator, a storage section for storing V-λ data, and a light intensity acquisition section for obtaining the light intensity detected by the detection section at a timing at which the light transmitted through the variable wavelength interference filter has the measurement target wavelength based on the voltage monitored by the voltage monitoring section. 1. A spectroscopic measurement device comprising:a first substrate;a second substrate opposed to the first substrate;a first reflecting film provided to the first substrate;a second reflecting film provided to the second substrate, and opposed to the first reflecting film across a predetermined gap;a gap amount changing section adapted to change the gap amount of the gap by deflecting the second substrate by applying a voltage;a detection section adapted to detect a light intensity of light interfered between the first reflecting film and the second reflecting film;a filter drive section adapted to apply an analog voltage continuously varying to the gap amount changing section;a voltage monitoring section adapted to monitor the voltage applied to the gap amount changing section;a storage section adapted to store V-λ data corresponding to a relationship between the voltage applied to the gap amount changing section and a wavelength of the light taken out by the first reflecting film and the ...

Absorption Spectrometer

An absorption spectrometer which measures a gas component concentration in a measured gas and which operates via wavelength modulation spectroscopy, wherein the light wavelength of a wavelength-tunable light source is periodically varied over a gas component absorption line of interest and simultaneously sinusoidally modulated with a high frequency and a low amplitude signal, and wherein the measurement signal of a detector is demodulated in a phase-sensitive manner at the frequency and/or a harmonic of the frequency and further analyzed, where modulation starts in each period or each n-th period with the frequency in a time interval before the beginning of the time function and is performed with a higher amplitude than during the time function to demodulate the measurement signal in a phase-synchronous manner, where a device provided for the phase-sensitive demodulation is synchronized during the time interval such that a cable for transmitting synchronization signals is no longer necessary.

APPARATUSES AND METHODS FOR ANOMALOUS GAS CONCENTRATION DETECTION

Embodiments of the disclosure are drawn to apparatuses and methods for anomalous gas concentration detection. A spectroscopic system, such as a wavelength modulated spectroscopy (WMS) system may measure gas concentrations in a target area. However, noise, such as speckle noise, may interfere with measuring relatively low concentrations of gas, and may lead to false positives. A noise model, which includes a contribution from a speckle noise model, may be used to process data from the spectroscopic system. An adaptive threshold may be applied based on an expected amount of noise. A speckle filter may remove measurements which are outliers based on a measurement of their noise. Plume detection may be used to determine a presence of gas plumes. Each of these processing steps may be associated with a confidence, which may be used to determine an overall confidence in the processed measurements/gas plumes. 124-. (canceled)25. An apparatus comprising:an optical system configured to record a set of gas concentration measurements based on received light from a target area;at least one processor; and extract anomalous ones of the set of gas concentration measurements above a threshold based on a noise model, wherein the noise model depends on measurement conditions; and', 'detect a gas plume based on a spatial relationship between at least some of the anomalous ones of the set of gas concentration measurements., 'a memory, the memory encoded with executable instructions, which when executed by the at least one processor, cause the apparatus to26. The apparatus of claim 25 , wherein the optical system comprises a laser spectroscopy system including a laser configured to direct light towards the target area and a detector configured to receive the light from the target area.27. The apparatus of claim 26 , wherein the laser is configured to modulate at a modulation frequency.28. The apparatus of claim 25 , wherein the executable instructions further comprise instructions to ...

Reference Switch Architectures for Noncontact Sensing of Substances

This relates to systems and methods for measuring a concentration and type of substance in a sample at a sampling interface. The systems can include a light source, optics, one or more modulators, a reference, a detector, and a controller. The systems and methods disclosed can be capable of accounting for drift originating from the light source, one or more optics, and the detector by sharing one or more components between different measurement light paths. Additionally, the systems can be capable of differentiating between different types of drift and eliminating erroneous measurements due to stray light with the placement of one or more modulators between the light source and the sample or reference. Furthermore, the systems can be capable of detecting the substance along various locations and depths within the sample by mapping a detector pixel and a microoptics to the location and depth in the sample. 120-. (canceled)21. A system for taking a measurement , comprising:a light source configured to output light to a sample;a first output region located at an interface of the system and configured to receive a first light from a first location within the sample;a second output region located at the interface of the system and configured to receive a second light from a second location within the sample;a detector; and first optics configured to receive the first light from the first output region and direct the first light from the first output region to the detector; and', 'second optics configured to receive the second light from the second output region and direct the second light from the second output region to the detector., 'an optics unit, comprising22. The system of claim 21 , further comprising a reference claim 21 , wherein:the light comprises is output to the sample and to the reference; and receive the second light from the reference; and', 'direct the second light to the detector., 'the optics unit further comprises third optics configured to23. The ...

HIGH SENSITIVITY FREQUENCY-DOMAIN SPECTROSCOPY SYSTEM

A system includes first and second radiation sources, first and second detectors, a signal digitizer, a controller, and an analyzer. The first and second radiation sources generate respective first and second beams of radiation to irradiate a target. The first beam and second beams each include a first wavelength operated at a first modulation frequency and a second wavelength operated at a second modulation frequency. The first and second detectors each include a photo-sensitive element that generate first or second detection signals, a Faraday shielding enclosure, a signal amplifier, and a frequency mixer to frequency-adjust the first or second detection signals. The controller provides timing information to inform an activation scheme of the first and second radiation sources and corresponding radiation detection events at the first and second detectors. The analyzer analyzes the first and second detection signals and determines at least amplitude and phase information of the scattered radiation. 1. A system comprising: a first wavelength at a first modulation frequency; and', 'a second wavelength at a second modulation frequency;, 'first and second radiation sources configured to generate respective first and second beams of radiation to irradiate a target along respective first and second paths, each of the first and second beams comprising a photo-sensitive element configured to receive scattered radiation resulting from the first and second beams and to generate first or second detection signals respective to the first or second detectors based on the received scattered radiation;', 'a Faraday shielding enclosure;', 'a signal amplifier configured to amplify the first or second detection signals; and', 'a frequency mixer configured to frequency-adjust the first or second detection signals;, 'first and second detectors each comprisinga signal digitizer configured to receive the first and second detection signals after the frequency-adjusting to generate a ...

NOISE REDUCTION APPARATUS AND DETECTION APPARATUS INCLUDING THE SAME

A noise reduction apparatus includes a first delaying/combining unit configured to output first and second pulse light beams, and a second delaying/combining unit configured to branch the first pulse light beam into two pulse light beams to output third and fourth pulse light beams and branch the second pulse light beam into two pulse light beams to output fifth and sixth pulse light beams. 1. A noise reduction apparatus comprising:a first delaying/combining unit configured to branch a pulse light beam of a first period into two pulse light beams, provide a first delay time between the two branched pulse light beams, and combine the two branched pulse light beams, to output a first pulse light beam polarized in a first direction and a second pulse light beam polarized in a direction orthogonal to the first direction and delayed by the first delay time with respect to the first pulse light beam;a second delaying/combining unit configured to branch the first pulse light beam into two pulse light beams, provide a second delay time between the two branched pulse light beams, combine the two branched pulse light beams, to output a third pulse light beam polarized in a second direction and a fourth pulse light beam polarized in a direction orthogonal to the second direction and delayed by the second delay time with respect to the third pulse light beam, branch the second pulse light beam into two pulse light beams, provide the second delay time between the two branched pulse light beams, and combine the two branched pulse light beams, to output a fifth pulse light beam polarized in the second direction and a sixth pulse light beam polarized in a direction orthogonal to the second direction and delayed by the second delay time with respect to the fifth pulse light beam, anda polarization adjustment unit configured to adjust a polarization direction of the first pulse light beam and a polarization direction of the second pulse light beam,wherein the polarization adjustment ...

Spectroscopy apparatus and method

There is presented a spectroscopic apparatus and method wherein an input light source that inputs pump light to a photon pair source. The photon pair source converts pump photons into signal and idler photon pairs. The photon pair source is, in some of examples described herein, tuneable so that the wavelength of the signal and idler photons can be changed by application of a tuning means. At least one of the signal and idler photons is made incident upon a medium under test. A heralding detection apparatus is used to detect any signal and idler photons output from the spectroscopy apparatus, wherein at least one of the photons of the pair has interacted with or been operated upon by the medium under test.

Method of determining the concentration of a gas component and spectrometer therefor

The invention relates to a method and to a spectrometer for determining the concentration of a gas component, wherein a light source of the spectrometer is operated as in WMS and thus a determination of the concentration can also take place in accordance with WMS and the measured data can, however, additionally be processed, namely a sorting takes place on the time axis, such that the concentration can be determined using the methods of DAS. 1. A method of determining the concentration of a gas component , the method comprising the steps of:producing a light beam having a wavelength variable in a wavelength range;guiding the light beam through a measurement volume in which the gas component to be determined is present, wherein the gas component has an absorption in the wavelength range;tuning the wavelength range, wherein an additional modulation of the wavelength takes place during the tuning at a modulation frequency which is high in comparison with a rate of the tuning so that a wavelength-to-time progression with a high-frequency modulation results, with the high frequency modulation having a phasing;detecting an intensity of the light beam after passing through the measurement volume;during the tuning, detecting measured points which contain an intensity value and which are each recorded at times which correspond to the same phasing of the high frequency modulation;producing an artificial measurement curve from the detected measured points; andevaluating the artificial measurement curve and determining a first concentration value therefrom.2. The method in accordance with claim 1 , further comprising the step of:producing a plurality of artificial measurement curves which each correspond to different phases.3. The method in accordance with claim 1 , further comprising the step of:determining the first concentration value from the artificial measurement curve in accordance with the method of direct absorption spectroscopy.4. The method in accordance with claim 1 ...

Cavity Ring-Down Spectroscopy having Interleaved Data Acquisition for Interference Mitigation

Interleaved data acquisition in optical spectroscopy is used to provide interference correction for time-varying interference. Measurements at a reference frequency are used to provide an estimate of the interference. These reference measurements are interleaved with the remaining measurements in order to provide estimates of the interference vs. time at relevant times. The interference being corrected can be spectrally structured or unstructured. 1. A method of performing optical absorption spectroscopy , the method comprising:providing an optical absorption instrument having a tunable optical source;performing optical absorption measurements of one or more analytes in a sample with the optical absorption instrument in a time-sequential series of measurements having interleaved first measurements and second measurements, wherein each of the first and second measurements includes at least a time stamp, an optical source frequency, and an optical loss;{'sub': 'ref', 'wherein all of the first measurements are performed at a reference frequency fof the optical source;'}{'sub': 'ref', 'wherein the second measurements include measurements performed at two or more optical source frequencies other than f;'}determining an interference optical loss spectrum vs. time from the first measurements and from an interference spectral model; andcorrecting the second measurements using the interference optical loss spectrum vs. time to provide interference-corrected second measurements.2. The method of claim 1 , wherein the interference spectral model is frequency-independent interference.3. The method of claim 2 ,{'sub': 'ref', 'wherein the reference frequency fis at a frequency away from spectral peaks of any constituents of the sample; and'}{'sub': 'ref', 'wherein correcting the second measurements comprises directly subtracting interference at fvs. time from the second measurements.'}4. The method of claim 2 ,{'sub': 'ref', 'wherein the reference frequency fis at a frequency of a ...

SEGMENTED CHIRPED-PULSE FOURIER TRANSFORM SPECTROSCOPY

An emission can be obtained from a sample in response to excitation using a specified range of excitation frequencies. Such excitation can include generating a specified chirped waveform and a specified downconversion local oscillator (LO) frequency using a digital-to-analog converter (DAC), upconverting the chirped waveform via mixing the chirped waveform with a specified upconversion LO frequency, frequency multiplying the upconverted chirped waveform to provide a chirped excitation signal for exciting the sample, receiving an emission from sample, the emission elicited at least in part by the chirped excitation signal, and downconverting the received emission via mixing the received emission with a signal based on the specified downconversion LO signal to provide a downconverted emission signal within the bandwidth of an analog-to-digital converter (ADC). The specified chirped waveform can include a first chirped waveform during a first duration, and a second chirped waveform during a second duration. 1generating a specified chirped waveform and a specified downconversion local oscillator (LO) frequency using a digital-to-analog converter (DAC);upconverting the chirped waveform via mixing the chirped waveform with a specified upconversion LO frequency;frequency multiplying the upconverted chirped waveform to provide a chirped excitation signal for exciting the sample;receiving an emission from the sample, the emission elicited at least in part by the chirped excitation signal; anddownconverting the received emission via mixing the received emission with a signal based on the specified downconversion LO signal to provide a downconverted emission signal within the bandwidth of an analog-to-digital converter (ADC);wherein the generating the specified chirped waveform includes generating a first chirped waveform during a first duration, and a second chirped waveform during a second duration, the first and second chirped waveforms including respective bandwidths ...

SYSTEM AND METHOD FOR INTERFEROMETRIC BASED SPECTROMETRY AND COMPACT SPECTROMETER USING SAME

An interference fringe pattern generator forms an interference fringe pattern from the light rays diffused from a region of an object positioned against a background. A planar array of detector pixels is arranged to capture an image of the interference fringe pattern. A storage medium records information indicative of intensity values of the image of the interference fringe pattern captured by a selected group of pixels of the planar array of detector pixels. The information is recorded as a function of the optical path difference values traversed by the diffused light rays through the interference fringe pattern generator for each of the pixels in the selected group of pixels. A processor determines the spectral characteristics of the object based on the information indicative of the intensity values recorded by the storage medium and the optical path difference values traversed by the diffused light rays. 1. A system comprising:an interference fringe pattern generator to form an interference fringe pattern from light rays diffused by a region of an object positioned against a background, wherein the light rays diffused by the region of the object originate from a focused source having an intensity greater than the illumination intensity of the background;a planar array of detector pixels arranged to capture an image of the interference fringe pattern;a storage medium coupled to the planar array of detector pixels, the storage medium recording information indicative of intensity values of the image of the interference fringe pattern captured by a selected group of pixels of the planar array of detector pixels, the information being recorded as a function of the optical path difference values traversed by the diffused light rays through the interference fringe pattern generator for each of the pixels in the selected group of pixels; andat least one processor coupled to the storage medium to determine the spectral characteristics of the object based on the ...

Method and Device for Generating Multispectral or Hyperspectral Light, for Hyperspectral Imaging and/or for Distance Measurement and/or 2D or 3D Profile Measurement of an Object by Means of Spectrometry

The invention relates to methods and to devices for generating multispectral illuminating light having an addressable spectrum, for adaptive multispectral imaging and for capturing structural and/or topographical information of an object or of the distance to an object. The illuminating device comprises a multispectral light source and a modulator for temporal modulation of the individual spectral components of the multispectral light source having modulation frequencies. The multispectral light source comprises at least one light source having a continuous, quasi-continuous, or frequency comb spectrum and wavelength-dispersive means, or an assembly or array of monochromatic or quasi-monochromatic light sources having emission wavelengths or emission wavelength bands which are different from one another in each case. The modulator comprises at least one electrically controllable three-dimensional light modulator, or a plurality of electronic control modules assigned to the individual monochromatic or quasi-monochromatic light sources. 1. An illuminating device for generating multispectral or hyperspectral illuminating light having an addressable spectrum , the illuminating device comprising:a multispectral light source;a modulation device which is configured to time-modulate individual spectral components of the multispectral light source with mutually different modulation frequencies, modulation frequency ranges, or modulation sequences, wherein(i) the multispectral light source comprises at least one light source having a continuous spectrum, a quasi-continuous spectrum, or frequency comb spectrum, and wavelength-dispersive element for spectral splitting of the light emitted by the light source in a plurality of spatially separate spectral components each having different wavelengths or wavelength bands, and the modulation device comprises at least one electrically controllable spatial light modulator, wherein the modulation device is configured to time-modulate ...

Biological material measuring apparatus and method of measuring biological material

An infrared light source radiates, to an ATR prism, infrared light in entirety or part of a wavelength range with absorption wavelengths of a biological material. The ATR prism is adherable to a measurement skin. A prism vibration controller is mounted on the ATR prism and vibrates the ATR prism perpendicular to a contact surface between the ATR prism and the measurement skin. A controller causes an infrared photodetector to detect infrared light in synchronization with the vibration of the ATR prism.

Fourier domain dynamic correction method for complex optical fringes in laser spectrometers

A method is provided for Fourier domain dynamic correction of optical fringes in a laser spectrometer. The method includes Fourier transforming a background spectrum contaminated with the optical fringes to obtain baseline fringes in a frequency domain. The method includes partitioning the baseline fringes in the frequency domain using bandpass filtering to obtain partitioned baseline fringes. The method includes reconstructing the partitioned baseline fringes as separate spectra using an inverse Fourier transform. The method includes constructing a fitting model to approximate the background spectrum by assigning a first and a second free parameter to each of partitioned baseline fringe components to respectively allow for drift and amplitude adjustments during a fitting of the fitting model. The method includes applying the fitting model to a newly acquired spectrum to provide an interpretation of the newly acquired spectrum having a reduced influence of spectral contamination on concentration retrieval.

CAVITY ENHANCED SPECTROSCOPY USING OFF-AXIS PATHS

Methods and apparatuses () of generating and processing a real-time time-domain cavity ringdown spectroscopy (CRDS) signal from absorbing species m an optical detection system having an optical ringdown cavity () using off-axis paths () are provided. At least one modulated light signal () is generated using one or more light sources (), each modulated at specified modulation frequency. Each modulated signal has harmonic frequency components and is input off-axis () relative to the cavity's optical axis (). The cavity contains mirrors () arranged in a predetermined configuration. The optical axis () is defined by a path passing through centers of mirrors (). The modulated light signal () is resonated off axis () without astigmatic optical. elements to produce CRDS signal and passes at least twice through cavity and across the mirrors () without interfering, with itself. An overall path length through cavity is greater than path length of optical axis. A photodetector detects () the CROS signal, which is demodulated () dependent upon selected harmonics. 1. A method of generating and processing a real-time time-domain cavity ringdown spectroscopy (CRI)S) signal from an absorbing species in an optical detection system having an optical ringdown cavity using off-axis paths , said optical ringdown cavity adapted for accepting , a sample of an absorbing species , said method comprising:generating at least one modulated light signal using one or more light sources, each light source being modulated at a specified modulation frequency, each modulated signal having a plurality of harmonic frequency components;inputting said at least one modulated light signal off-axis to said optical ringdown cavity in relation to an optical axis of said optical ringdown cavity, said optical ringdown cavity comprising a plurality of mirrors arranged in a predetermined configuration within said optical ringdown cavity and said optical axis defined by a path passing through the centers of said ...

Method and Gas Analyzer for Measuring the Concentration of a Gas Component in a Sample Gas

Gas analyzer and method for measuring the concentration of a gas component in a sample gas, wherein the wavelength of the light of a wavelength-tunable light source is varied within periodically successive sampling intervals and, in the process, additionally modulated with a frequency to perform wavelength dependent sampling of an absorption line of a gas component to be measured in the sample gas.

Integrated spectrometers with single pixel detector

An integrated waveguide based spectrometer is described. The spectrometer comprises a sensing region for receiving multi-wavelength radiation for irradiating a sample in the sensing region, a wavelength demultiplexing element arranged for capturing said multi-wavelength radiation after interaction with the sample and for providing a number of wavelength demultiplexed radiation outputs or a number of different groups of wavelength demultiplexed radiation outputs, an integrated modulator for differently modulating the different demultiplexed radiation outputs or different groups of demultiplexed radiation outputs, and a multiplexer element for multiplexing the differently modulated demultiplexed radiation outputs or the differently grouped demultiplexed radiation outputs.

High Throughput Multiplex Spectroscopy

A method for measuring a property of radiation from different sources such as moving particles or different spatial locations on each particle includes providing a spatial modulator common to all of the sources having a sequence of configurations, each of which configurations causes the radiation flux to pass along paths to respective modulation ports and cycling the common spatial modulator past each of the modulation ports so that the sequence of configurations is applied to each modulation port. The sequence of configurations comprises an ordered array of optical elements on a substrate. In one embodiment, the modulator is arranged in a circle around an axis of rotation of a rotating singulation disk. At least one source is a reference source which has not interacted with the source to be analyzed and the sample and reference sources are compared. 1. A method for measuring a property of each of a plurality of radiation fluxes where each radiation flux arises from a different one of a plurality of radiation sources , comprising the steps ofcollecting each radiation flux independently of others of the plurality of radiation fluxes;providing a spatial modulator common to all of the radiation sources;the common spatial modulator having a sequence of configurations, each of which configurations causes the radiation flux to pass along one or more modulated flux pathseach radiation flux being associated with a respective one of a plurality of separate modulation ports where each radiation flux passes to a respective one of the modulation ports;cycling the common spatial modulator past each of the modulation ports so that the sequence of configurations is applied to each modulation port;providing a plurality of detectors associated with the radiation fluxes and for each radiation flux measuring an amplitude of the radiation flux along each modulated flux path;and analyzing the radiation flux amplitudes associated with each modulation port to provide information about a ...

Dual optical frequency comb light-emitting device

A dual optical frequency comb light-emitting device includes a first optical-frequency-comb laser source that includes a first laser resonator having a first optical path length, a second optical-frequency-comb laser source that includes a second laser resonator having a second optical path length different from the first optical path length, and an optical coupler that causes a first portion of first optical-frequency-comb laser light emitted from the first laser resonator to enter the second laser resonator. The first optical-frequency-comb laser source outputs a second portion of the first optical-frequency-comb laser light to an outside. The second optical-frequency-comb laser source outputs second optical-frequency-comb laser light emitted from the second laser resonator to the outside.

ASSEMBLY FOR SPECTROPHOTOMETRIC MEASUREMENTS

An assembly for measurements of one or more optical parameters of a medium is disclosed. The assembly comprises a light sheet generator, a light intensity modulator, a holder for a sample, and an optical sensor.

Method for Correcting a Wavelength and Tuning Range of a Laser Spectrometer

A method for correcting a wavelength and a tuning range of a laser spectrometer in which the light from a wavelength-tunable laser diode, after being radiating through a gas, is detected and evaluated, wherein the laser diode is periodically driven with a current ramp, such that a time-resolved absorption spectrum of the gas is obtained upon the detection of the light, where in order to correct the wavelength and the tuning range of the laser spectrometer, a first step involves readjusting the central wavelength of the laser diode via the temperature thereof and based on the position of one of two different selected absorption lines in the detected absorption spectrum, and a second step involves correcting the tuning range of the laser diode via the gradient of the current ramp such that the spacing of the two absorption lines in the detected absorption spectrum remains constant. 113.-. (canceled)14. A method for correcting a wavelength and a tuning range of a laser spectrometer , in which light of a wavelength-tunable laser diode is detected and evaluated after radiating through a gas , the laser diode being periodically driven with a current ramp , such that a time-resolved absorption spectrum of the gas is obtained upon the detection of the light , whereincomparing, in a currently obtain absorption spectrum an actual position of an absorption line of the gas with a target position of the same absorption line detected and stored in a preceding one-off adjustment of the laser spectrometer;changing, in a correction step, with a deviation of the actual position of the absorption line from the target position, a temperature of the laser diode until an actual position corresponds to the target position;comparing, in the absorption spectrum currently obtained, the actual position of a further absorption line with the target position of the same absorption line detected and stored in a preceding one-off adjustment of the laser spectrometer; andchanging, in a further ...

Method and apparatus for optical asynchronouos sampling signal measurements

A method and a system for measuring an optical asynchronous sample signal. The system for measuring an optical asynchronous sampling signal comprises a pulsed optical source capable of emitting two optical pulse sequences with different repetition frequencies, a signal optical path, a reference optical path, and a detection device. Since the optical asynchronous sampling signal can be measured by merely using one pulsed optical source, the complexity and cost of the system are reduced. A multi-frequency optical comb system using the pulsed optical source and a method for implementing the multi-frequency optical comb are further disclosed.

Dual-Comb Spectroscopy

A dual-comb spectrometer comprising two lasers outputting respective frequency combs having a frequency offset between their intermode beat frequencies. One laser acts as a master and the other as a follower. Although the master laser is driven nominally with a DC drive signal, the current on its drive input line nevertheless oscillates with an AC component that follows the beating of the intermode comb lines lasing in the driven master laser. This effect is exploited by tapping off this AC component and mixing it with a reference frequency to provide the required frequency offset, the mixed signal then being supplied to the follower laser as the AC component of its drive signal. The respective frequency combs in the optical domain are thus phase-locked relative to each other in one degree of freedom, so that the electrical signals obtained by multi-heterodyning the two optical signals are frequency stabilized. 1. A source module for a dual-comb spectrometer comprising:{'b': '1', 'sub': 'rep,1', 'a first semiconductor laser source operable to output a first light signal containing a first frequency comb (C) consisting of a finite series of discrete frequencies separated by a first intermode beat frequency (f);'}a first electrical driver connected to the first semiconductor laser source to apply a first drive current signal to cause generation of the first light signal;{'b': '2', 'sub': 'rep,2', 'a second semiconductor laser source operable to output a second light signal containing a second frequency comb (C) consisting of a finite series of discrete frequencies separated by a second intermode beat frequency (f) having a frequency offset from the first intermode beat frequency;'}a second electrical driver connected to the second semiconductor laser source to apply a second drive current signal to cause generation of the second light signal;{'sub': 'rep,1', 'an electrical output line from the first semiconductor laser source arranged to extract an AC modulation ...

Pulse Width Modulation of Continuum Sources for Determination of Chemical Composition

A light source and a method for its use in an optical sensor are provided, the light source including a resistively heated element. The light source includes a power circuit configured to provide a pulse width modulated voltage to the resistively heated element, the pulse width modulated voltage including: a duty cycle with a first voltage; and a pulse period including a period with a second voltage, wherein: the duty cycle, the first voltage, and the pulse period are selected so that the resistively heated element is heated to a first temperature; and the first temperature is selected to emit black body radiation in a continuum spectral range. Also provided is an optical sensor for determining a chemical composition including a light source as above. 1. A light source for use in an optical sensor , the light source comprising:a resistively heated element; and a duty cycle with a first voltage; and', the duty cycle, the first voltage, and the pulse period are selected so that the resistively heated element is heated to a first temperature; and', 'the first temperature is selected to emit black body radiation in a continuum spectral range., 'a pulse period including a period with a second voltage, wherein], 'a power circuit configured to provide a pulse width modulated voltage to the resistively heated element, the pulse width modulated voltage comprising2. The light source of wherein the second voltage is lower than the first voltage.3. The light source of wherein the second voltage is zero.4. The light source of any one of claim 1 , claim 1 , or wherein the duty cycle claim 1 , the second voltage claim 1 , and the pulse period are selected so that the resistively heated element is heated to a second temperature lower than the first temperature.5. The light source of wherein the second temperature is selected to emit black body radiation in a second continuum spectral range.621-. (canceled). 1. Technical FieldEmbodiments disclosed herein relate to the field of ...

METHOD FOR MEASURING CONCENTRATION OF A GAS COMPONENT IN A MEASUREMENT GAS

A method in which the wavelength of the light of a tunable light source is varied periodically over an absorption line of interest for the gas component to measure the concentration of a gas component in a measurement gas based on one of two measurement methods of direct absorption spectroscopy and wavelength modulation spectroscopy and, where in the case of wavelength modulation spectroscopy, the wavelength of the light is additionally sinusoidally modulated at a high frequency and with a small amplitude, where the intensity of the light is detected after transradiation of the measurement gas and processed to yield a measurement result, and where in order to increase the accuracy and reliability of the measurement, the two measurement methods are applied simultaneously during each period, or alternately in consecutive periods, and their results are combined by averaging to form the measurement result. 1. A method for measuring concentration of a gas component in a measurement gas based on two measurement methods comprising direct absorption spectroscopy and wavelength modulation spectroscopy , comprising:varying a wavelength of light of a tunable light source periodically over an absorption line of interest for the gas component;additionally sinusoidally modulating a wavelength of the light of the tunable light source at a high frequency and with a small amplitude in cases of wavelength modulation spectroscopy; anddetecting an intensity of the light after transradiation of the measurement gas and processing the light to yield a measurement result, the two measurement methods being applied simultaneously during each period, or alternately in consecutive periods, and their results being combined by averaging to form the measurement result.2. The method as claimed in claim 1 , wherein results of the two measurement methods are weighted differently in the averaging.3. The method as claimed in claim 2 , wherein the results of the two measurement methods are weighted ...

Method and Apparatus for Hyperspectral Imaging

A method and apparatus for the generation of hyperspectral images for an object consisting of a broad band light projection systems, a means of modulating the wavelength of the light, one or more sensors for observing the reflected light, one or more electronic means of synchronizing and extracting data from the sensor, one or more sensors for registering position, one or more calibration methods for rationalizing the data, and one or more algorithms for analyzing the data to produce the hyperspectral image. 1) A method for hyperspectral imaging of an object or objects using a “CHIRP” modulation , the method comprising a light source of sufficient bandwidth and brightness , a tunable optical filter , such as an acousto-optic-transmission filter , with driver capable of “CHIRPING ,” brightfield or darkfield illumination optics , lens of sufficient resolution to measure the samples , imaging optics , one or more sensor(s) of sufficient sensitivity and readout rate to enable sampling of the “CHIRP” signal , hardware and software to enable the creation of the “CHIRP” source and demodulation of the “CHIRP” signal , calibration method for normalizing the spectroscopic response , and hardware and software required for synchronizing data sampling with location of sample.2) A method for hyperspectral imaging of an object or objects using a “CHIRP” modulation , the method comprising a light source of sufficient bandwidth and brightness , a tunable optical filter , such as an acousto-optic-transmission filter , with driver capable of “CHIRPING ,” brightfield or darkfield illumination optics , lens of sufficient resolution to measure the sample , galvanometric scanner(s) with mirrors and programmable driver capable of scanning entire field of view , imaging optics , one or more sensor(s) of sufficient sensitivity and readout rate to enable sampling of the “CHIRP” signal , hardware and software to enable the creation of the “CHIRP” source and demodulation of the “CHIRP” signal , ...

AMPLIFIED MULTIPLEX ABSORPTION SPECTROSCOPY

An optically thin sample of a sample material is analyzed by propagating probe electromagnetic radiation from a beam source along a plurality of different ray paths, directing each ray so that each ray path intersects upon the sample at a plurality of different locations where the rays interact with the sample material to cause a modification of the ray. The rays received at each of a plurality of detection spatial region are measured separately and the measurements analyzed to provide information about at least one property of the sample material at each interaction location. An analysis is carried out to trace the path of probe radiation from a location at the probe beam source to the detection spatial region on the detection surface so as to identify the interaction locations so as to provide information about the presence of target material at each interaction location. 1. A method for analyzing an optically thin sample for presence of a target material comprising:locating the optically thin sample which potentially contains the target material;the sample including a plurality of sample locations each containing an unknown sample material, a known sample material, or no sample;propagating a beam of probe electromagnetic radiation from a beam source so that rays within the beam are directed along a plurality of different ray paths;directing each ray using optical elements so that each ray path intersects upon the sample a plurality of times at a plurality of different intersection locations;at each of the plurality of interaction locations causing the rays to interact with the sample material to cause a modification of the ray;after intersecting sample locations directing each ray path to intersect a detection surface where the detection surface is divided into a plurality of detection spatial regions;measuring separately the rays received at each detection spatial region where the measurements contain information about the interaction of sample materials along ...

TERAHERTZ SPECTROMETER AND METHOD FOR REDUCING PHOTOMIXING INTERFERENCE PATTERN

Highly advantageous spectrometer systems and associated methods are disclosed which utilize phase modulation in conjunction with first and second harmonic detection to reduce or eliminate negative impacts from interference patterns. 1. A method for determining terahertz frequency spectral information of a material in a sampling area , comprising:generating a first light at a first frequency;generating a second light at a second frequency such that the first frequency and second frequency are different from one another by a difference frequency;modulating the phase of at least a portion of the first light relative to the second light by passing the portion of the first light through a phase modulator to produce a phase modulated light at a phase modulation frequency;photo-mixing the phase modulated light and the second light and generating a difference frequency signal at the difference frequency based at least in part on the photo-mixing;transmitting the difference frequency signal through the sampling area wherein the difference frequency signal is modified to include the terahertz frequency spectral information by the material;receiving the modified difference frequency signal from the sampling area and generating a received signal in response;photo-mixing the unmodulated first light and the second light to generate a detection oscillation;mixing the received signal and the detection oscillation to generate a detector signal, the detector signal including an interference pattern resulting from photo-mixing and the terahertz frequency spectral information;detecting a first harmonic component of the detector signal using a first harmonic of the modulation frequency;detecting a second harmonic component of the detector signal using a second harmonic of the modulation frequency; andcombining the first harmonic component and the second harmonic component to produce a power curve of the terahertz frequency spectral information in which the interference pattern is at ...

Method and System for the Relative Referencing of a Target Gas in an Optical Measuring System for Laser Spectroscopy

A method for operating an optical measuring system including a wavelength-tunable temperature-stabilized laser light source for measuring the concentration of a target gas component in a measured gas, wherein an instantaneous base current I DC_ZG,act corresponding to a wavelength λ ZG of a target gas absorption line is set so that a wavelength distance Δλ DC defined during calibration between a target gas absorption line for a target gas component and a reference gas absorption line for a reference gas component is maintained. During operation, a relative temperature difference in the laser light source, defined in advance during calibration, between the operating points selected at the time of calibration of the reference gas, with a base current I DC_RG,cal , and the target gas component, with a base current I DC_ZG,cal , is maintained by determining the required instantaneous base current I DC_ZG,act for the target gas component, as a function of an instantaneous base current I DC_RG,act for the reference gas. The system includes a measuring system for carrying out the method.

APPARATUS AND METHOD FOR PROCESSING SPECTRUM ACCORDING TO CHANGE IN TEMPERATURE OF OBJECT

Provided is a spectrum processing apparatus for removing noise, caused by a change in temperature, from a spectrum. The spectrum processing apparatus includes: a temperature modulator configured to perform modulation of a temperature of an object; a spectrometer configured to obtain a first spectrum based on the temperature of the object that is changed by the modulation; and a spectrum processor configured to extract a temperature change vector based on the first spectrum, and to correct a second spectrum based on the extracted temperature change vector. 1. A spectrum processing apparatus comprising:a temperature modulator configured to perform modulation of a temperature of an object;a spectrometer configured to obtain a first spectrum based on the temperature of the object which is changed by the modulation; anda spectrum processor configured to extract a temperature change vector, which represents characteristics of respective wavelengths according to a change in the temperature, based on the first spectrum, and to correct a second spectrum based on the extracted temperature change vector.2. The spectrum processing apparatus of claim 1 , wherein the temperature modulator comprises:a heater configured to supply heat energy to the object; anda temperature sensor configured to detect the temperature of the object.3. The spectrum processing apparatus of claim 1 , wherein the temperature modulator is further configured to perform the modulation to change the temperature of the object by 1° C. or more.4. The spectrum processing apparatus of claim 1 , wherein the temperature modulator is further configured to perform the modulation at least one time to change the temperature of the object within a predetermined range of temperature.5. The spectrum processing apparatus of claim 4 , wherein the temperature modulator is further configured to successively perform first modulation and second modulation claim 4 , such that the temperature of the object is continuously ...

PORTABLE OPTICAL SPECTROSCOPY DEVICE FOR ANALYZING GAS SAMPLES

A portable optical spectroscopy device is disclosed for analyzing gas samples and/or for measurement of species concentration, number density, or column density. The device includes a measuring chamber with the gas sample to be analyzed, a light source with at least one laser diode for emitting a laser beam along a light path running through the measuring chamber at least in certain regions, means for modulating the wavelength of the light beam emitted by the light source, and an optical detector device having a first optical detector and at least one second optical detector. At least a part of the light emitted by the laser diode is detected after the light has passed through the measuring chamber m-times, and at least a part of the light emitted by the laser diode is detected with the at least one second optical detector after the light has passed through the measuring chamber n-times, where n>m applies. 1. A portable optical spectroscopy device for analyzing a gas sample and/or for measurement of species concentration , number density , or column density , the device comprising the following:a measuring chamber with the gas sample to be analyzed;a light source with at least one laser diode for emitting a light beam along a light path running through the measuring chamber at least in certain regions, wherein the at least one laser diode of the light source is a semiconductor laser diode;control circuitry configured to modulate a wavelength of the light beam emitted by the light source;an optical detector device having a first optical detector and at least one second optical detector, the first and the at least one second optical detector being arranged with respect to the laser diode such that with the first optical detector at least a part of the light emitted by the laser diode is detected after the light has passed through the measuring chamber m-times, and at least a part of the light emitted by the laser diode is detected with the at least one second optical ...

Method and system for reduction of influence of baseline distortion in absorption spectroscopy measurements

A method and system for reducing the effect of distortions on the baseline signal in an absorption spectroscopy system used for the detection or measurement of chemical species in a medium, whereby one or more correlations or convolutions are performed on the signal using a kernel function. The shape of the kernel function is chosen to reduce the influence of the baseline distortions on the processed measurand determination. The kernel function may also be chosen to enhance the absorption signal.

THIN-LAYERED DEVICES IN COMPRESSIVE SENSING SPECTROSCOPY

A spectroscopic method using either tunable or preset non-tunable thin-layered devices or a combination of both to modulate compressed-sensing-compliant, spectral modulations and to use intensity measurements of each respective spectral modulation to numerically reconstruct an estimated spectral distribution of the spectral signal such that the estimated spectral distribution is characterized by a totality of spectral bands exceeding the number of spectral modulations by about one half an order-of-magnitude or more. 1. A spectroscopic method comprising:using one or more, thin-layered photonic devices to modulate a plurality of spectral modulations from a spectral signal, each spectral modulation characterized by at least two peaks when depicted in a modulated transmission or reflection response on a display device;obtaining one intensity measurement from each of the spectral modulations; andusing a processor to numerically resolve an estimated spectral distribution of the spectral signal from the intensity measurements, the estimated spectral distribution characterized by a totality of spectral bands exceeding in number the plurality of spectral modulations.2. The spectroscopic method of claim 1 , wherein the one or more thin-layered photonic devices includes non-tunable photonic devices.3. The spectroscopic method of claim 2 , wherein the one or more thin-layered photonic devices includes a tunable claim 2 , single-cell liquid-crystal-retarder.4. The spectroscopic method of claim 3 , wherein using one or more thin-layered photonic devices to modulate a plurality of spectral modulations claim 3 , includes adjusting a voltage applied to the liquid-crystal-retarder5. The spectroscopic method of claim 4 , wherein the adjusting a voltage applied to the liquid-crystal-retarder is implemented in increments between 0.001 volts-to 0.5 volts.6. The spectroscopic method of claim 1 , wherein the one or more thin-layered photonic devices includes a tunable reflection-based thin ...

Far-Infrared Imaging Device and Far-Infrared Imaging Method

Provided are an imaging method and device for imaging using far infrared light that make it possible to quickly image a subject without producing damage or a non-linear phenomenon in the subject. A variable-frequency coherent light source is used, illumination light from the light source is irradiated onto a linear area on an imaging subject, transmitted or reflected light is used to form an image of the imaging subject, a non-linear optical crystal is used for wavelength conversion, and a one-dimensional or two-dimensional array sensor is used to image the imaging subject while the imaging subject is moved in at least one direction. 1. A far-infrared imaging apparatus , comprising:a wavelength-tunable far-infrared light source in which first pump light and first near-infrared light are incident onto a non-linear optical crystal to generate first far-infrared light;an illumination optical system that irradiates the first far-infrared light on a sample;a far-infrared light imaging optical system that forms an image of the sample;a detecting non-linear optical crystal onto which second far-infrared light transmitting through or reflected from the sample and second pump light are incident, thereby generating second near-infrared light;a sensor that detects the image; anda detecting optical system that introduces light emitted from the detecting non-linear optical crystal onto the sensor,wherein the second far-infrared light is incident obliquely onto an upper surface of the detecting non-linear optical crystal,wherein the second pump light is incident onto a side surface of the detecting non-linear optical crystal, andwherein the side surface of the detecting non-linear optical crystal onto which the second pump light is incident is approximately parallel to an optical axis of the second far-infrared light.2. The far-infrared imaging apparatus according to claim 1 ,wherein the second pump light in incident obliquely onto the side surface of the detecting non-linear ...

NOISE REDUCTION APPARATUS AND DETECTION APPARATUS INCLUDING THE SAME

A noise reduction apparatus includes a first delaying/combining unit configured to output first and second pulse light beams, and a second delaying/combining unit configured to branch the first pulse light beam into two pulse light beams to output third and fourth pulse light beams and branch the second pulse light beam into two pulse light beams to output fifth and sixth pulse light beams. 1. A noise reduction apparatus comprising:a first delaying/combining unit configured to branch a pulse light beam of a first period into two pulse light beams, provide a first delay time between the two branched pulse light beams, and combine the two branched pulse light beams, to output a first pulse light beam polarized in a first direction and a second pulse light beam polarized in a direction orthogonal to the first direction and delayed by the first delay time with respect to the first pulse light beam; anda second delaying/combining unit configured to branch the first pulse light beam into two pulse light beams, provide a second delay time between the two branched pulse light beams, combine the two branched pulse light beams, to output a third pulse light beam polarized in a second direction and a fourth pulse light beam polarized in a direction orthogonal to the second direction and delayed by the second delay time with respect to the third pulse light beam, branch the second pulse light beam into two pulse light beams, provide the second delay time between the two branched pulse light beams, and combine the two branched pulse light beams, to output a fifth pulse light beam polarized in the second direction and a sixth pulse light beam polarized in a direction orthogonal to the second direction and delayed by the second delay time with respect to the fifth pulse light beam,wherein a light intensity ratio between the first pulse light beam and the second pulse light beam is 1:1,wherein the light intensity ratio between the third pulse light beam and the fourth pulse light ...

Cavity Enhanced Absorption Spectroscopy using a piecewise tunable laser and hierarchical wavelength determination

Improved cavity enhanced absorption spectroscopy is provided using a piecewise tunable laser by using a lookup table for laser tuning that is configured specifically for this application. In preferred embodiments this is done in combination with a laser control strategy that provides precise wavelength determination using cavity modes of the instrument as a reference. 1. Apparatus for performing cavity ring down spectroscopy , the apparatus comprising:an optical source having a tunable emission wavelength, wherein the optical source has two or more tuning inputs, and wherein tuning of the optical source is piecewise continuous with respect to variation of any one of its tuning inputs;an optical cavity having two or more mirrors and configured to accept an optical input from the optical source, wherein the optical cavity is also configured to accept a sample gas such that light circulating in the optical cavity passes through the sample gas;a ringdown controller configured to monitor the light circulating in the optical cavity and configured to couple and interrupt coupling of light between the optical source and the optical cavity;a tuning controller configured to tune the optical source in a setpoint mode and in a control mode;wherein the control mode is closed-loop control of a single control input of the optical source to tune output wavelength of the optical source;wherein the setpoint mode is an open-loop tuning of the optical source using all tuning inputs according to a lookup table configured to maximize mode-hop free wavelength range around each output wavelength when using the control mode;wherein the tuning controller is configured to perform the following steps in sequence for each target wavelength of the optical source:setting the output wavelength of the optical source to within +/−0.3 nm of the target wavelength using the setpoint mode;waiting for a first settling time of 2 ms or less to let the optical source reach a steady state;activating the ...

CAPILLARY ABSORPTION SPECTROMETER AND PROCESS FOR ISOTOPIC ANALYSIS OF SMALL SAMPLES

A capillary absorption spectrometer and process are described that provide highly sensitive and accurate stable absorption measurements of analytes in a sample gas that may include isotopologues of carbon and oxygen obtained from gas and biological samples. It further provides isotopic images of microbial communities that allow tracking of nutrients at the single cell level. It further targets naturally occurring variations in carbon and oxygen isotopes that avoids need for expensive isotopically labeled mixtures which allows study of samples taken from the field without modification. The process also permits sampling in vivo permitting real-time ambient studies of microbial communities. 1. A capillary absorption spectrometer for analysis of low-volume samples , comprising:an excitation laser configured to supply a non-pulsed excitation beam to an absorption device having an absorption volume configured to receive the excitation beam from the excitation laser into a sample gas introduced therein;a modulation device comprising a second or higher order bias-T diplexer coupled to the excitation laser that suppresses harmonics from a repetitive linear current ramp source therein and sub-harmonics from a dither-modulated current source therein such that the amplitude of the harmonics and the sub-harmonics is at least 60 dB lower than the modulation waveform selected and provided to the excitation laser; andan optical isolation device disposed between the excitation laser and an absorption device that randomizes the pointing angle and the spread of the excitation beam that suppresses feedback noise induced by reflection of the excitation beam incident upon, and from within, the absorption device back to the excitation laser.2. The spectrometer of claim 1 , further including a laser ablation device that couples to a catalytic reactor and a transfer device claim 1 , the laser ablation device is configured to deliver ablated sample particulates to the catalytic reactor for ...

OPTICAL ABSORBANCE MEASUREMENTS WITH SELF-CALIBRATION AND EXTENDED DYNAMIC RANGE

Detector data representative of an intensity of light that impinges on a detector after being emitted from a light source and passing through a gas over a path length can be analyzed using a first analysis method to obtain a first calculation of an analyte concentration in the volume of gas and a second analysis method to obtain a second calculation of the analyte concentration. The second calculation can be promoted as the analyte concentration upon determining that the analyte concentration is out of a first target range for the first analysis method. 120-. (canceled)21. A method comprising:receiving, by at least one processor, detector data representative of an absorbance of light emitted from a light source as the light passes through a volume of gas over a path length, the volume of gas comprising an analyte at an analyte concentration, the light having an added modulation frequency;first determining, by the at least one processor, a first calculation of the analyte concentration, the first determining comprising first analyzing the detector data demodulated to remove the added modulation frequency, the first analyzing having a first target range;second determining, by the at least one processor, a second calculation of the analyte concentration, the second determining comprising second analyzing the detector data without demodulating, the second analyzing having a second target range that does not fully overlap the first concentration range; andpromoting, by the at least one processor, the second calculation as the analyte concentration when the determining that the first calculation of the analyte concentration indicates that the analyte concentration is outside of the first target range.22. A method as in claim 21 , further comprising controlling the light source to add the modulation frequency to the light.23. A method as in claim 22 , wherein the first analyzing comprises use of modulation spectroscopy and the second analyzing comprises use of direct ...

CAVITY BUILDUP DISPERSION SPECTROMETER AND PERFORMING CAVITY BUILDUP DISPERSION SPECTROSCOPY

A cavity buildup dispersion spectrometer includes a shutter that modulates coherent electromagnetic radiation at a shutter frequency; and produces modulated electromagnetic radiation; a frequency shifter that frequency shifts the modulated electromagnetic radiation to a shifter frequency and produces frequency shifted radiation; a resonator that produces cavity radiation from the frequency shifted radiation and the coherent electromagnetic radiation, receives an analyte; subjects the analyte to cavity radiation, and transmits the cavity radiation as transmitted electromagnetic radiation; and a receiver that: produces a detector signal from the transmitted electromagnetic radiation, such that the detector signal includes a beat frequency that corresponds to a change in a motion of resonator that includes a change in the distance between the mirrors or a change of refractive index of the analyte in the intracavity space. 1. A cavity buildup dispersion spectrometer comprising:a shutter that receives coherent electromagnetic radiation, modulates the coherent electromagnetic radiation at a shutter frequency; and produces modulated electromagnetic radiation from the coherent electromagnetic radiation;a frequency shifter in communication with the shutter and that receives the modulated electromagnetic radiation from the shutter, frequency shifts the modulated electromagnetic radiation by a shifter frequency; and produces frequency shifted radiation that is different from the modulated electromagnetic radiation by the shifter frequency; a plurality of mirrors separated by a distance;', 'an intracavity space interposed between the mirrors having the distance as a length; and', receives the frequency shifted radiation from the frequency shifter;', 'receives coherent electromagnetic radiation;', 'produces cavity radiation, in the intracavity space, from the frequency shifted radiation and the coherent electromagnetic radiation;', 'receives an analyte in the intracavity space ...

SYSTEM AND METHOD FOR RAPID AND ACCURATE TRACE GAS MEASUREMENT

An embodiment of a system for measuring trace gas concentration is described that comprises a laser absorption spectrometer configured to detect an absorbance measure from a trace gas, as well as a temperature value and a pressure value that correspond to an environment in a gas cell; and a computer having executable code stored thereon configured to perform a method comprising: receiving the absorbance value, the temperature value, and the pressure value; defining a fitting range associated with the trace gas; applying a curve fitting model in the fitting range to the absorbance value using the temperature value and the pressure value as model parameters; and producing a concentration measure of the trace gas. 1. A system for measuring trace gas concentration , comprising:a laser absorption spectrometer configured to detect an absorbance measure from a trace gas, as well as a temperature value and a pressure value that correspond to an environment in a gas cell; and receiving the absorbance value, the temperature value, and the pressure value;', 'defining a fitting range associated with the trace gas;', 'applying a curve fitting model in the fitting range to the absorbance value using the temperature value and the pressure value as model parameters; and', 'producing a concentration measure of the trace gas., 'a computer having executable code stored thereon, wherein the executable code is configured to perform a method comprising2. The system of claim 1 , wherein:the computer performs the method over a computation time that is shorter than a data acquisition rate of the laser absorption spectrometer.3. The system of claim 2 , wherein:the computer operates in a time domain format that analyzes a plurality of the absorbance values as they are acquired over time and reports the concentration measure of the trace gas in real-time.4. The system of claim 1 , wherein:the curve fitting model comprises a peak tracking feature that compensates for laser source instability.5. ...

Fourier domain dynamic correction method for complex optical fringes in laser spectrometers

A method is provided for Fourier domain dynamic correction of optical fringes in a laser spectrometer. The method includes Fourier transforming a background spectrum contaminated with the optical fringes to obtain baseline fringes in a frequency domain. The method includes partitioning the baseline fringes in the frequency domain to obtain partitioned baseline fringes. The method includes reconstructing the partitioned baseline fringes as separate spectra. The method includes constructing a fitting model to approximate the background spectrum by assigning a first and a second free parameter to each of partitioned baseline fringe components to respectively allow for drift and amplitude adjustments during a fitting of the fitting model. The method includes applying the fitting model to a newly acquired spectrum to provide an interpretation of the newly acquired spectrum having a reduced influence of spectral contamination on concentration retrieval.

CONCURRENT ACTIVATION OF MULTIPLE ILLUMINATION SOURCES FOR SAMPLE ANALYSIS

Technologies are generally described for concurrent activation of multiple illumination sources to analyze a sample. A controller may be configured to activate the illumination sources substantially simultaneously, where a current or voltage of each activated illumination source is modulated at a different frequency by respective circuit drivers of the controller. Each activated illumination source may be configured to illuminate the sample with light at a different emission wavelength, and one or more detectors may be configured to detect a composite signal from the sample in response to the illumination. The composite signal may include multiple returned signals, where each returned signal corresponds to light emitted from one of the activated illumination sources at a respective emission wavelength. One or more filters, each associated with a respective modulation frequency of one activated illumination source, may be configured to extract each returned signal from the composite signal for analysis. 1. An apparatus comprising:a plurality of illumination sources configured to illuminate a sample with light, wherein each of the plurality of illumination sources has a different emission wavelength;a controller configured to activate the plurality of illumination sources substantially simultaneously, wherein each of the plurality of illumination sources are configured to be activated at a different modulation frequency; andone or more detectors positioned adjacent to the plurality of illumination sources, wherein the one or more detectors are configured to detect a composite signal from the sample in response to the illumination, wherein the composite signal comprises a plurality of returned signals, each of the plurality of returned signals corresponding to light emitted from one of the plurality of illumination sources at a respective emission wavelength.2. The apparatus of claim 1 , wherein the controller includes a plurality of driver circuits claim 1 , and ...

ANALYSIS APPARATUS, PROGRAM FOR ANALYSIS APPARATUS, AND ANALYSIS METHOD

The present invention is adapted to include: a light source adapted to emit reference light that is light whose wavelength is modulated at a predetermined modulation frequency; a light detector adapted to detect the intensity of measurement target light that is light after the reference light has transmitted through the measurement target component, and the intensity of the reference light; a first calculation part adapted to calculate an intensity ratio logarithm that is the logarithm of the ratio between the intensity of the measurement target light and the intensity of the reference light; a frequency component extraction part adapted to lock-in detect the intensity ratio logarithm with a reference signal having a frequency n times the modulation frequency; and a second calculation part adapted to, on the basis of the result of the detection by the frequency component extraction part, calculate the concentration or absorbance of the measurement target component. 1. An analysis apparatus adapted to analyze a measurement target component contained in a sample , the analysis apparatus comprising:a light source adapted to emit reference light that is light whose wavelength is modulated at a predetermined modulation frequency;a light detector adapted to detect intensity of measurement target light that is light after the reference light has transmitted through the sample, and intensity of the reference light;a first calculation part adapted to calculate an intensity ratio logarithm that is a logarithm of a ratio between the intensity of the measurement target light and the intensity of the reference light;a frequency component extraction part adapted to, from the intensity ratio logarithm, extract a frequency component having a frequency n times (n is an integer equal to or more than 1) the modulation frequency; anda second calculation part adapted to, on a basis of a result of the frequency component extraction by the frequency component extraction part, calculate ...

SEGMENTED CHIRPED-PULSE FOURIER TRANSFORM SPECTROSCOPY

An emission can be obtained from a sample in response to excitation using a specified range of excitation frequencies. Such excitation can include generating a specified chirped waveform and a specified downconversion local oscillator (LO) frequency using a digital-to-analog converter (DAC), upconverting the chirped waveform via mixing the chirped waveform with a specified upconversion LO frequency, frequency multiplying the upconverted chirped waveform to provide a chirped excitation signal for exciting the sample, receiving an emission from sample, the emission elicited at least in part by the chirped excitation signal, and downconverting the received emission via mixing the received emission with a signal based on the specified downconversion LO signal to provide a downconverted emission signal within the bandwidth of an analog-to-digital converter (ADC). The specified chirped waveform can include a first chirped waveform during a first duration, and a second chirped waveform during a second duration. 1. (canceled)2. A method , comprising:receiving a first emission signal from a sample, the first emission signal spanning a first bandwidth and elicited at least in part by a first excitation signal applied to sample;mixing the first emission signal with a first local oscillator (LO) to generate a first downconverted emission signal within a conversion bandwidth of an analog-to-digital converter (ADC);digitizing the first downconverted emission signal with the ADC to generate a first digital signal;receiving a second emission signal from the sample, the second emission signal spanning a second bandwidth different than the first bandwidth and elicited at least in part by a second excitation signal applied to the sample;mixing the second emission signal with a second local oscillator (LO) to generate a second downconverted emission signal within the conversion bandwidth of the ADC;digitizing the second downconverted emission signal with the ADC to generate a second ...

STAND-OFF SPECTROMETRY SYSTEMS AND METHODS

Stand-off spectrometry systems and methods are described herein. One system includes a laser source configured to emit a single-spectral light, and an optical frequency comb (OFC) coupled to the laser source and configured to generate, using the single-spectral light, a multi-spectral light to determine an absorption spectrum of a substance. 1. A stand-off spectrometry system , comprising:a laser source configured to emit a single-spectral light; andan optical frequency comb (OFC) coupled to the laser source and configured to generate, using the single-spectral light, a multi-spectral light to determine an absorption spectrum of a substance.2. The system of claim 1 , wherein the system includes a tuner coupled to the laser source and configured to alter a wavelength of the single-spectral light.3. The system of claim 2 , wherein the tuner is coupled to the OFC and configured to alter a wavelength range of the multi-spectral light.4. The system of claim 2 , wherein the tuner is configured to alter a wavelength of the single-spectral light by changing a temperature of the single-spectral light.5. The system of claim 1 , wherein the system includes:a grating configured to split the absorption spectrum into a number of absorption spectrum sections; anda number of detectors, wherein each detector is configured to receive a different one of the absorption spectrum sections.6. The system of claim 5 , wherein the number of absorption spectrum sections each have a predetermined frequency range.7. A method for providing stand-off spectrometry claim 5 , comprising:tuning a single-spectral laser source and an optical frequency comb (OFC) for receiving a number of absorption wavelengths of a substance; anddetermining an absorption spectrum for the substance based, at least in part, on the number of absorption wavelengths.8. The method of claim 7 , wherein tuning the single-spectral laser source and the OFC includes changing a temperature of the single-spectral laser source and ...

Real-Time Programmable ICE and Applications in Optical Measurements

A system and method are disclosed for configuring an integrated computational element (ICE) to measure a property of a sample of interest. The system includes an illumination source to provide a sample light which is reflected from or transmitted through a sample. A dispersive element disperses the sample light into wavelength portions. An intensity modulation device having an array of electronically controllable modulation elements is disclosed that forms a pattern which modulates the dispersed sample light. Collection optics focuses the modulated sample light on a detector, which generates a signal that correlates to a property of the sample. The electronically controllable modulation elements can be readily altered to conform to a different measurable property of a sample of interest as desired. 1. An optical system for the measurement of sample properties comprising:an illumination source to provide a sample light;a dispersive element to disperse the sample light into wavelength portions;an intensity modulation device comprising an array of modulation elements electronically controllable to provide a modulated sample light including a selected portion of the dispersed sample light;a signal detector; andcollection optics to direct the modulated sample light to the detector.2. The optical system of wherein the modulation elements are electronically controllable to provide a complementary modulated sample light including a second selected portion of the dispersed sample light.3. The optical system of wherein a difference between a sample light pattern and a complementary sample light pattern is a linear regression vector associated with a measurable property of the sample.4. The optical system of wherein a ratio of a sample light pattern to a sum of the pattern and a complementary sample light pattern is a linear regression vector associated with a measurable property of the sample.5. The optical system of further comprising a processor circuit and a memory circuit ...

Online monitor for trace sodium in high-purity water, and online monitoring method and device thereof

An online monitor for trace sodium in high-purity water, and an online monitoring method and device thereof are provided. Under the control of an embedded industrial computer, an injection-calibration system conveys calibrated water samples and to-be-measured water samples to a flame atomization system continuously and stably. The flame atomization system forms a negative pressure field using a high-purity hydrogen-oxygen mixture as carrier gas, draws in the to-be-measured water samples for atomization, mixing and droplet separation, and then ignites a characteristic spectrum which emits sodium at a high-temperature inner cone. A photoelectric sensor system quickly scans the characteristic spectrum of sodium, and outputs a second-order differential modulation sodium spectrum after removing background interferences. A data acquisition system acquires an analog signal of the second-order differential modulation sodium spectrum, converts the analog signal into a digital signal and outputs the digital signal to the embedded industrial computer for real-time monitoring and control.

QCL Spectroscopy System and Applications Therefor

A spectroscopy system comprising at least two laser modules, each of the laser modules including a laser cavity, a quantum cascade gain chip for amplifying light within the laser cavity, and a tuning element for controlling a wavelength of light generated by the modules. Combining optics are used to combine the light generated by the at least two laser modules into a single beam and a sample detector detects the single beam returning from a sample. 1. A spectroscopy system comprising:at least two laser modules, each of the laser modules including a laser cavity, a quantum cascade gain chip for amplifying light within the laser cavity, and a tuning element for controlling a wavelength of light generated by the modules;combining optics for combining the light generated by the at least two laser modules into a single beam; anda sample detector for detecting the single beam returning from a sample.2. The spectroscopy system of claim 1 , further comprising a gas cell claim 1 , from which the sample detector detects the single beam to analyze gas in the gas cell.3. The spectroscopy system of claim 2 , wherein the laser modules and the gas cell are contained within a housing.4. The spectroscopy system of claim 3 , wherein the housing is a portable hand-held housing.5. The spectroscopy system of claim 1 , further comprising a fiber optic probe and a fiber optic cable claim 1 , wherein the fiber optic cable connects the spectroscopy system to the fiber optic probe.6. The spectroscopy system of claim 5 , wherein the fiber optic probe is a grazing angle probe.7. The spectroscopy system of claim 5 , wherein the fiber optic probe is an attenuated total reflection probe.8. A spectroscopy method comprising:combining light generated by at least two laser modules into a single beam, in which each of the laser modules includes a laser cavity, a quantum cascade gain chip for amplifying light within the laser cavity and a tuning element for controlling a wavelength of light generated ...

INFRARED (IR) SPECTROSCOPY SYSTEM

A system is provided comprising an FTIR spectrometer configured to obtain a Fourier Transformed infrared (FTIR) spectrum of a Peripheral Blood Mononuclear Cells (PBMC) sample of the subject; a data processor operable with the FTIR spectrometer, and configured to analyze the infrared (IR) spectrum of the Peripheral Blood Mononuclear Cells (PBMC) sample of the subject by assessing a characteristic of the sample of the subject at at least one wavenumber; and an output unit, configured to generate an output indicative of the presence of a solid tumor, based on the infrared (IR) spectrum. Other embodiments are also provided. 1. A system comprising:an FTIR spectrometer configured to obtain a Fourier Transformed infrared (FTIR) spectrum of a Peripheral Blood Mononuclear Cells (PBMC) sample of the subject; 'an output unit, configured to generate an output indicative of the presence of a solid tumor, based on the infrared (IR) spectrum.', 'a data processor operable with the FTIR spectrometer, and configured to analyze the infrared (IR) spectrum of the Peripheral Blood Mononuclear Cells (PBMC) sample of the subject by assessing a characteristic of the sample of the subject at at least one wavenumber; and'}2. The system according to claim 1 , wherein the data processor is configured to compare at the at least one wavenumber claim 1 , the infrared spectrum of the subject to an infrared spectrum obtained from a PBMC sample from a person without a solid tumor claim 1 , to detect a difference between the infrared spectrum of the PBMC sample of the subject and the infrared spectrum obtained from the PBMC sample from the person without a solid tumor.3. The system according to claim 1 , wherein the data processor is configured to calculate a second derivative of the infrared (IR) spectrum of the PBMC sample and claim 1 , based on the second derivative of the infrared (IR) spectrum claim 1 , to generate an output indicative of the presence of a solid tumor.4. The system according to ...

Method for measuring the concentration of a gas component in a measuring gas

A method for measuring the concentration of a gas component in a measuring gas. An absorption line of the gas component is varied as a function of the wavelength of the light of a wavelength-tunable light source within a periodically sequential scanning interval. The absorption line of the gas component is modulated with a frequency (f 0 ) Modulated light is guided through the measuring gas onto a detector. A measurement signal generated by the detector is demodulated upon determining a harmonic (nf 0 ) of the frequency (f 0 ). A measurement result is produced by fitting a setpoint curve to the profile of the demodulated measurement signal. Both demodulated measurement signal and setpoint cure are filtered with the aid of the same filter function. The filter function is operative to suppress noise signal components of the demodulated measurement signal that disturb both signal components of the demodulated measurement signal and the setpoint curve.

Sweep Control of an Optical Heterodyne Measurement System

Described herein is a system and method of controlling an optical heterodyne measurement system (). The measurement system () has a tunable laser () for generating a local oscillator signal, an optical input () for receiving an input optical signal () and a mixing module () for mixing the local oscillator signal with the input optical signal to generate an output optical measurement signal. One embodiment provides a method including the steps of: a) receiving an input electrical drive signal for driving the tunable laser () to produce a laser output having a spectral linewidth and peak central frequency; b) coupling the input electrical drive signal with an electrical linewidth control signal () to selectively broaden the spectral linewidth; and c) during a measurement period, selectively tuning the central frequency of the laser in a stepwise manner across a predetermined frequency spectrum at predefined tuning increments. 1. A method of controlling an optical heterodyne measurement system , the measurement system having a tunable laser for generating a local oscillator signal , an optical input for receiving an input optical signal and a mixing module for mixing the local oscillator signal with the input optical signal to generate an output optical measurement signal; the method including the steps of:a) receiving an input electrical drive signal for driving the tunable laser to produce a laser output having a spectral linewidth and peak central frequency, an initial spectral linewidth of the laser output having a first spectral width;b) coupling the input electrical drive signal with a linewidth control signal to selectively broaden the spectral linewidth to a second spectral width; andc) during a measurement period, selectively tuning the central frequency of the laser in a stepwise manner across a predetermined frequency spectrum at predefined tuning increments.2. A method according to wherein the tuning increment is defined based on the second spectral width.3 ...

Hyperspectral imaging in a light deficient environment

An endoscopic imaging system for use in a light deficient environment includes an imaging device having a tube, one or more image sensors, and a lens assembly including at least one optical elements that corresponds to the one or more image sensors. The endoscopic system includes a display for a user to visualize a scene and an image signal processing controller. The endoscopic system includes a light engine having an illumination source generating one or more pulses of electromagnetic radiation and a lumen transmitting one or more pulses of electromagnetic radiation to a distal tip of an endoscope.

Method for Optical and Electrical Signal Processing of a Multi-Heterodyne Signal Generated by a Multi-Mode Semi-Conductor Laser and Detection Device Utilizing that Method

A method for optical and electrical signal processing of a multi-heterodyne signal generated by a multi-mode semi-conductor laser, for a system comprising two laser sources and an sample interaction unit. At least the beam of one of the laser passes through said sample interaction unit before being combined on a detector. The first laser is tuned ( 40=>42 ) by an amount keeping the tuning result within the available detector bandwidth ( 55 ). Then the second laser is roughly tuned by the same amount as the tuning of the first laser to bring back the signal to the vicinity ( 48 ) of the original place in the RF-domain and within the bandwidth ( 55 ) of the detector. The tuning steps are repeated with different value of mode spacing for reconstructing the sample spectrum and provide a high resolution image of the dip ( 41 ) absorption line ( 40 ).

External Cavity Laser Source

A tunable laser source that includes multiple gain elements and uses a spatial light modulator in an external cavity to produce spectrally tunable output is claimed. Several designs of the external cavity are described, targeting different performance characteristics and different manufacturing costs for the device. Compared to existing devices, the tunable laser source produces high output power, wide tuning range, fast tuning rate, and high spectral resolution. 1. A sensor system , comprising: (i) one or more tunable gain elements providing sources of optical radiation at different wavelengths;', '(ii) a spectral dispersion device acting on the radiation produced by the gain elements to produce radiation dispersed into separate wavelengths; and', '(iii) a spatial light modulator (SLM) defining a plurality of programmable sub-apertures that determine the output wavelengths of the laser; and, '(a) a frequency agile tunable laser that has an external cavity, the laser comprising(b) a control system that automatically performs spectroscopic signal processing on the SLM by applying a mathematical transform to generate a set of output laser wavelengths for interrogating a sample.2. The sensor system of wherein the control system controls the SLM so as to perform random access in a time domain to any laser wavelength within the spectra of the gain elements.3. The sensor system of wherein the control system controls the SLM so as to perform chemical analysis or material identification in a short time period by reducing the number of laser wavelengths used claim 1 , confining them to spectral regions of interest for characterizing one or more of the following: a specific analyte claim 1 , expected interferents or a spectral background.4. The sensor system of where the spectral regions of interest are not contiguous.5. The sensor system of wherein the control system controls the SLM so as to accomplish time-multiplexed modulation of multiple laser wavelengths claim 1 , or a ...

COMPACT INFRARED SPECTROMETER SYSTEMS AND METHODS FOR MEASURING VIBRATIONAL SPECTRUM OF MATERIALS AND SUBSTANCES

Systems and methods for measuring a fundamental mode vibrational spectrum of materials and substances in the Mid-IR spectral range of 2.5 μm to 14 μm wavelength. are disclosed herein. In one embodiment, a Mid-infrared absorption spectrometer (MIRAS) system includes an infrared Micro-Electro-Mechanical System (MEMS) single element emitter light source. The light source is electrically pulsed and emits electromagnetic radiation in the wavelength range from 2.5 μm to 14 μm and has an integral energy concentrating optic to provide energy for a spectral absorption process. The system includes a scanning high-efficiency infrared spectral grating with self-calibrating feature, configured so that incident energy having absorption information for the spectral absorption process of a sample is within a predefined threshold of a grating blaze angle. The system also includes a single-element thermal detector to receive output energy having the absorption information from the infrared spectral grating. 1. A Mid-infrared absorption spectrometer (MIRAS) system comprising: an infrared Micro-Electro-Mechanical System (MEMS) single element emitter light source , wherein the light source is electrically pulsed and emits electromagnetic radiation in the wavelength range from 2.5 μm to 14 μm and includes an integral energy concentrating optic to provide energy for a spectral absorption process;a scanning high-efficiency infrared spectral grating with self-calibrating feature, configured so that incident energy having absorption information for the spectral absorption process of a sample is within a predefined threshold of a grating blaze angle; anda single-element thermal detector to receive output energy having the absorption information from the infrared spectral grating.2. The MIRAS system of claim 1 , further comprising:a micro-machined silicon Attenuated Total Reflection (ATR) sample plate, either as stationary or removable and disposable is utilized.3. The MIRAS system of claim 1 ...

Gas Concentration Measurement by 2F Signal Trough Distance

A computer-implemented method for measuring gas concentration from a 2f signal in wavelength modulation spectroscopy is presented. The computer-implemented method includes emitting a beam of light from a laser to pass through a gas sample, calculating a gas measurement value from the gas sample via a trough distance calculator using a trough distance of a gas absorption line's 2f signal, calibrating the gas measurement value via a multi-point calibration process, and outputting the gas measurement value to a user interface of a computing device. 1. A computer-implemented method executed on a processor for measuring gas concentration from a 2f signal in wavelength modulation spectroscopy , the method comprising:emitting a beam of light from a laser to pass through a gas sample;calculating a gas measurement value from the gas sample via a trough distance calculator using a trough distance of a gas absorption line's 2f signal;calibrating the gas measurement value via a multi-point calibration process; andoutputting the gas measurement value to a user interface of a computing device.2. The method of claim 1 , wherein the gas concentration is a linear function of trough distance claim 1 , the gas concentration given by C=p+p·D claim 1 , where C is gas concentration claim 1 , D is trough distance claim 1 , and p claim 1 , pare coefficients.3. The method of claim 1 , wherein the gas measurement value is calculated by employing a peak trough height in combination with the trough distance claim 1 , the peak trough height calculated from a peak trough height calculator.4. The method of claim 3 , wherein the gas concentration is a linear function of the peak trough height and a linear function of the trough distance claim 3 , the concentration given by C=p+p·H and by C=p+p·D claim 3 , where C is gas concentration claim 3 , D is trough distance claim 3 , H is peak trough height claim 3 , and p-pare coefficients.5. The method of claim 3 , wherein the gas concentration is a ...

Path fluctuation monitoring for frequency modulated interferometer

A method is presented for determining path length fluctuations in an interferometer using a reference laser with an arbitrary frequency with respect to the measured light. The method includes: injecting reference light along signal paths of the interferometer; measuring interference between the reference light at an output of the interferometer; determining an optical phase difference between the reference light in the two signal paths of the interferometer by measuring intensity modulation of the interference between the reference light and subtracting an intended frequency modulation from the measured intensity modulation; accumulating an unwrapped phase difference between the reference light in the two signal paths of the interferometer, where the unwrapped phase difference is defined in relation to a reference; and determining path length fluctuation of light in the interferometer using the unwrapped phase difference.

Hyperspectral imaging with tool tracking in a light deficient environment

An endoscopic imaging system for use in a light deficient environment includes an imaging device having a tube, one or more image sensors, and a lens assembly including at least one optical elements that corresponds to the one or more image sensors. The endoscopic system includes a display for a user to visualize a scene and an image signal processing controller. The endoscopic system includes a light engine having an illumination source generating one or more pulses of electromagnetic radiation and a lumen transmitting one or more pulses of electromagnetic radiation to a distal tip of an endoscope.

DEVICES AND METHODS FOR SENSING TARGETS USING PHOTOTHERMAL SPECKLE DETECTION

A device, and corresponding method, can include a pump light source configured to be modulated at a pump modulation and to irradiate a target specimen. The device can also include a probe light source arranged to generate a speckle pattern from the target specimen, as well as a sensor configured to detect changes in at least one of position and intensity of one or more speckle lobes of the speckle pattern having correlation with the pump modulation. The device and method can be used for non-contact monitoring and remote sensing of surfaces, gases, liquids, particles, and other target materials by analyzing speckle pattern changes as a function of pump light irradiation. Advantages can include much higher sensitivity than existing methods; the ability to use visible probe wavelengths for uncooled, low-cost visible detectors with high spatial resolution; and the ability to obtain target material properties without detecting infrared light. 1. A device comprising:a pump light source configured to be modulated at a pump modulation and to irradiate a target specimen;a probe light source arranged to generate a speckle pattern from the target specimen; anda sensor configured to detect changes in at least one of position and intensity of one or more speckle lobes of the speckle pattern having correlation with the pump modulation.2. The device of claim 1 , wherein the pump modulation is on a time scale shorter than a time scale of blurring of the speckle pattern claim 1 , and wherein the sensor is configured to detect the changes in at least one of position and intensity on a time scale shorter than the time scale of blurring the speckle pattern.3. The device of claim 1 , further comprising a correlator configured to perform a frequency analysis to determine correlation of the changes in at least one of position and intensity of the one or more speckle lobes with a frequency of the pump modulation.4. The device of claim 1 , further comprising a processor configured to ...

ROOM-TEMPERATURE QUANTUM NOISE LIMITED SPECTROMETRY AND METHODS OF THE SAME

According to one embodiment, a heterodyne detection system for detecting light, includes: a first input aperture configured to receive first light from a scene input; a second input aperture configured to receive second light from a local oscillator input; a broadband local oscillator configured to provide the second light to the second input aperture; a dispersive element configured to disperse the first light and the second light; and a final condensing lens coupled to a detector. The final condensing lens is configured to concentrate incident light from a primary condensing lens onto the detector. The detector is configured to sense a frequency difference between the first light and the second light; and the final condensing lens comprises a plasmonic condensing lens. Methods for forming a plasmonic condensing lens to enable room temperature quantum noise limited spectrometry are also disclosed. 1. A heterodyne detection system for detecting light , comprising:a first input aperture configured to receive first light from a scene input;a second input aperture configured to receive second light from a local oscillator input;a broadband local oscillator configured to provide the second light to the second input aperture;a dispersive element configured to disperse the first light and the second light; anda final condensing lens coupled to a detector;wherein the final condensing lens is configured to concentrate incident light from a primary condensing lens onto the detector;wherein the detector is detector configured to sense a frequency difference between the first light and the second light; andwherein the final condensing lens comprises a plasmonic condensing lens.2. The heterodyne detection system as recited in claim 1 , wherein the detector is an infrared detector.3. The heterodyne detection system as recited in claim 1 , wherein the detector is a square-law detector.4. The heterodyne detection system as recited in claim 1 , wherein the detector comprises a type ...

Apparatus and Method for Measurement of Optical Frequency Shifts

An apparatus and method for measuring small changes in the centroid of the spectrum of a light field by conversion of optical frequency centroid shifts into time delays are described. A time delay for a particular frequency of light is created by directing the light into an optically dispersive system that converts the change in center frequency to a change in transit time through the system as the dispersive element causes different colors to travel at different speeds. Examples of such dispersive elements include, but are not limited to, optical fibers, bulk materials, volumetric or fiber Bragg gratings, and grating or prism based pulse stretchers. This time delay can be measured, by detecting the change in transit time (or time of flight through the dispersive element) by using a detector such as a photodiode, PMT, etc. that converts the incident optical pulse train into an electronic pulsed signal. The phase of the periodic electronic signal provides a measure of the timing delay of the pulse, and can be determined by adapting standard methods of electronic oscillator phase detection relative to a reference electronic oscillator clock. 1. A method for measuring the shift in the center optical frequency of light from a light source , from that of a known center optical frequency comprising:directing the light from the light source into an optically dispersive system, whereby the center frequency experiences a first transit time through the dispersive system;measuring the first transit time;directing the known center optical frequency into the optically dispersive system, whereby the frequency of the known center frequency experiences a second transit time through the dispersive system;measuring the second transit time; andgenerating a time delay from the difference of the first transit time and the second transit time;from which the shift in the center optical frequency is determined.2. The method of claim 1 , wherein the optically dispersive system is chosen ...

METHOD FOR THE NON-DESTRUCTIVE TESTING OF A CASING

A method for the non-destructive testing of the heating of a part made from polymer material, the method comprising the following steps: a) carrying out a measurement by infrared spectroscopy on a part to be tested and extracting therefrom at least one of absorbance values and transmittance values according to a spatial frequency; and b) from the measurement of at least one of absorbance and transmittance, determining the period of time during which said region of the part to be tested has been subjected to a given heating temperature and determining said heating temperature, using a reference database comprising at least one of absorbance measurements and transmittance measurements, the measurements established over a plurality of reference samples made from polymer material that have been subjected to a given temperature during a given period of time. 1. A method for non-destructive testing of a heating of a part made from polymer material , the method comprising:a) carrying out a measurement by infrared spectroscopy at a region of said part to be tested and extracting therefrom at least one of absorbance values and a transmittance values according to a spatial frequency;b) from at least one of the absorbance values and transmittance values, determining an interval of spatial frequencies relating to an oxidation of a polymer of said region of the part; andc) from the measurement of at least one of absorbance and transmittance in said interval of spatial frequencies, determining a period of time during which said region of the part to be tested has been subjected to a given heating temperature and determining said heating temperature, using a reference database comprising at least one of absorbance measurements and transmittance measurements, the measurements established over a plurality of reference samples made from polymer material that have been subjected to a given temperature during a given period of time.2. The method of claim 1 , further comprising: ...

METHOD FOR DETERMINING ABSORPTION BANDS

The present invention concerns a method for determining at least one absorption band in a spectrum, the method at least comprising the steps of:—providing a measured absorption spectrum from the sample,—providing a calculation spectrum,—from the calculation spectrum, extracting at least one absorption band,—calculating a residual spectrum by removing each extracted absorption band from the calculation spectrum, testing whether a predefined stop criterion is fulfilled by the residual spectrum,—if the stop criterion is not fulfilled, using the residual spectrum as the calculation spectrum and iterating the extracting step, the forming step, the calculating step and the testing step, and—if the stop criterion is fulfilled, outputting each extracted absorption band. 1. Method for determining at least one absorption band in a spectrum , a spectrum being the evolution of a absorption quantity with regards to a wavelength quantity in a predefined range of wavelength quantity , the absorption quantity being a quantity representative of the absorption and the wavelength quantity being a quantity representative of the wavelength , each absorption band being a distribution profile associated to at least one covalent bond of chemical species present in a sample , the distribution profile being characterized by mathematical parameters , the method at least comprising the steps of:providing a measured absorption spectrum from the sample,providing a calculation spectrum which is equal to the measured absorption spectrum,from the calculation spectrum, extracting at least one absorption band,forming an absorption band population by grouping each extracted absorption band,calculating a residual spectrum by removing each extracted absorption band from the calculation spectrum,testing whether a predefined stop criterion is fulfilled by the residual spectrum,if the stop criterion is not fulfilled, using the residual spectrum as the calculation spectrum and iterating the extracting step, ...

DEVICE AND METHOD FOR WAVELENGTH VARIATION OF AT LEAST ONE LIGHT SOURCE FOR DERIVATIVE SPECTROSCOPY

Disclosed is a spectroscopy device, including an analysis zone for receiving a sample; at least one light-emitting diode arranged to emit a light beam towards the analysis zone, having a luminous intensity spectral profile in a working wavelength interval; unit for varying with time the luminous intensity spectral profile emitted by the diode in the working wavelength interval of the diode; a detector, arranged to receive, during a variation with time of the luminous intensity spectral profile emitted by the diode, the light beam emitted by the diode and having crossed the analysis zone, and supplying a detection signal of the light beam emitted by the diode and received by the detector, in the form of a signal which depends on at least one characteristic representative of the luminous intensity spectral profile of the light-emitting diode. Application to derivative spectroscopy. 115-. (canceled)16. Spectroscopy device , comprising:{'b': '2', 'an analysis zone (), intended to receive a sample,'}{'b': 3', '2', '4, 'at least one light-emitting diode (), arranged in order to emit towards the analysis zone () a light beam () having a spectral profile of light intensity within a wavelength working range,'}{'b': '3', 'said device comprising, for each light-emitting diode (){'b': 5', '3, 'means () for time variation of the spectral profile of light intensity emitted by this diode () within the wavelength working range of this diode,'}{'b': 6', '8', '9, 'a detector (, , ), arranged in order to{'b': 3', '4', '3', '2, 'receive, during a variation over time of the spectral profile of light intensity emitted by this diode (), the light beam () emitted by this diode () and having passed through the analysis zone (),'}{'b': '3', 'supply a detection signal (A′) of the light beam emitted by this diode () and received by the detector, in the form of a signal which depends on at least one characteristic representative of the spectral profile of light intensity of this light-emitting ...

GENERATING LASER PULSES AND SPECTROSCOPY USING THE TEMPORAL TALBOT EFFECT

A method of generating laser pulses () includes: creating a circulating light field in resonator device () having resonator length L and an intra-cavity dispersion and configured for supporting light field resonator modes, and generating a pulse train of laser pulses () by a mode-locking mechanism. Laser pulses () are generated with a repetition frequency and provide a frequency comb with carrier frequency ωand comb modes in frequency space. The intra-cavity dispersion is selected such that round trip phases ϕ have a dependency on frequency ω according to 4. The method according to claim 1 , wherein the frequency difference between neighboring comb frequencies (Δ=ω−ω) is in a radio frequency range.5. The method according to claim 1 , wherein the intra-cavity dispersion is set with at least one fiber Bragg grating claim 1 , at least one intracavity prism and/or at least one intracavity grating included in the resonator device.6. The method according to claim 1 , wherein the resonator device is a fiber ring laser.7. A spectroscopy method for obtaining a spectral response of a sample claim 1 , comprising the steps of{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'generating a pulse train of laser pulses with a method according to ,'}applying the laser pulses on the sample under investigation,detecting the laser pulses with a detector device,analyzing a detector signal of the detector device for obtaining beat signals created by the comb modes of the pulse train of laser pulses, anddetermining the spectral response of the sample from the beat signals.8. The spectroscopy method according to claim 7 , further comprising the steps ofdetecting a reference portion of the pulse train of laser pulses without an application on the sample with the detector device, andanalyzing a reference detector signal of the detector device for obtaining reference beat signals created by the comb modes of the reference portion of the pulse train of laser pulses, whereinthe spectral ...

REFERENCE SWITCH ARCHITECTURES FOR NONCONTACT SENSING OF SUBSTANCES

This relates to systems and methods for measuring a concentration and type of substance in a sample at a sampling interface. The systems can include a light source, optics, one or more modulators, a reference, a detector, and a controller. The systems and methods disclosed can be capable of accounting for drift originating from the light source, one or more optics, and the detector by sharing one or more components between different measurement light paths. Additionally, the systems can be capable of differentiating between different types of drift and eliminating erroneous measurements due to stray light with the placement of one or more modulators between the light source and the sample or reference. Furthermore, the systems can be capable of detecting the substance along various locations and depths within the sample by mapping a detector pixel and a microoptics to the location and depth in the sample. 1. A system for measuring a concentration of a substance in a sample at a sampling interface , the system comprising:a light source configured to emit a first light including one or more wavelengths;one or more optics;one or more modulators configured to modulate at least a portion of the first light, the one or more modulators located between the one or more optics and the sampling interface;a reference comprising one or more spectroscopic properties;a first detector configured to detect the portion of the first light; and send one or more first signals to the light source, and', 'receive one or more second signals from the first detector., 'logic configured to2. The system of claim 1 , wherein the one or more modulators include an optical chopper located between the light source and the sampling interface or the reference.3. The system of claim 1 , wherein the reference is a reflector configured with a size that is greater than or equal to a size of the first light emitted from the light source.4. The system of claim 1 , further comprising a filter claim 1 , the ...

Method for Calibration-Free Scanned-Wavelength Modulation Spectroscopy for Gas Sensing

A method of calibration-free scanned-wavelength modulation spectroscopy (WMS) absorption sensing is provided by obtaining absorption lineshape measurements of a gas sample on a sensor using 1/-normalized WMS-2/j where an injection current to an injection current-tunable diode laser (TDL) is modulated at a frequency ̂ where a wavelength modulation and an intensity modulation of the TDL are simultaneously generated, extracting using a numerical lock-in program and a low-pass filter appropriate band-width WMS-< Подробнее

TERAHERTZ SPECTROSCOPY SYSTEM AND METHOD

A terahertz spectrometer includes: a terahertz-wave emitter and a terahertz receiver elements. The terahertz wave generated by means of generating beat frequency corresponding to the difference between two rapidly tunable continuous wave lasers. Having a difference in time between the interrogating signal and the reference signal at the receiver end side, which corresponds to intermediate frequency (IF), not centered around the baseband, i.e. zero Hertz. The offset step size of the intermediate frequency from zero Hertz is linearly correlated to the position of the interrogated object position. 128-. (canceled)29. A method for use in spectroscopic measurements of a sample , the method comprising: generating inspecting and reference radiation components corresponding to respectively first and second pairs of light beams of the same beat frequency contents being swept according to a predetermined pattern and directing said inspecting and reference radiation components to a detector along first and second different paths , the sample being located in the first path , said predetermined pattern being selected so as to induce a desired frequency difference between a frequency of the inspecting radiation component and the reference radiation component interacting at the detector , a signal resulting from the interaction between said inspecting and reference radiation components being indicative of one or more properties of the sample at a location where said inspecting radiation interacts with the sample.30. The method of claim 29 , further comprising controlling at least one of said predetermined pattern and propagation of the inspecting and reference radiation components to the detector claim 29 , said controlling of said predetermined pattern of the frequency sweeping comprises concurrently affecting a first claim 29 , global frequency sweeping rate during a certain time period and a local modulation of the frequency sweeping with a second higher sweeping rate.31. A ...

Room-temperature quantum noise limited spectrometry and methods of the same

According to one embodiment, a method of forming a plasmonic condensing lens for room temperature quantum noise limited (QNL) infrared (IR) spectrometry includes: forming a silicon cone on a substrate; coating the silicon cone with a highly reflective material; and modifying the silicon cone using focused ion beam (FIB) modification to permit transmittance of light through the silicon cone.

SYSTEM FOR MEASURING LEVELS OF RADIATION REFLECTING FROM SEMICONDUCTOR MATERIAL FOR USE IN MEASURING THE DOPANT CONTENT THEREOF

A system and method of non-contact measurement of the dopant content of semiconductor material by reflecting infrared (IR) radiation off of the material into an integrating sphere to scatter the received radiation and passing portions of the radiation through band pass filters of differing wavelength ranges, comparing the level of energy passed through each filter and calculating the dopant content by referencing a correlation curve made up of known wafer dopant content for that system. 1. A system for measuring levels of radiation reflected from semiconductor material for use in measuring the dopant content of the material , comprising:a) an infrared radiation source;b) a modulator for modulating the radiation from the infrared radiation source;c) an integrating sphere having a first opening for receiving the modulated radiation from the source and a second opening for receiving radiation reflected from the material, the sphere configured to scatter the received radiation reflected from the material within the sphere;d) a collimator configured to direct the radiation from the infrared radiation source through the sphere to impact the material at an angle from the normal with reference to the material, the angle sufficient to minimise radiation from being reflected directly back to the collimator and also to minimise radiation entering the sphere before reflecting from the material;e) a first baffle positioned within the sphere to prevent the received radiation reflected from the material from travelling to the first band pass filter without first scattering within the sphere;f) a second baffle positioned within the sphere to prevent the received radiation reflected from the material from travelling to the second band pass filter without first scattering within the sphere;g) a first band pass or edge pass filter positioned to receive a first portion of the received radiation reflected from the material, the first band pass or edge pass filter configured to pass a ...

SEGMENTED CHIRPED-PULSE FOURIER TRANSFORM SPECTROSCOPY

An emission can be obtained from a sample in response to excitation using a specified range of excitation frequencies. Such excitation can include generating a specified chirped waveform and a specified downconversion local oscillator (LO) frequency using a digital-to-analog converter (DAC), upconverting the chirped waveform via mixing the chirped waveform with a specified upconversion LO frequency, frequency multiplying the upconverted chirped waveform to provide a chirped excitation signal for exciting the sample, receiving an emission from sample, the emission elicited at least in part by the chirped excitation signal, and downconverting the received emission via mixing the received emission with a signal based on the specified downconversion LO signal to provide a downconverted emission signal within the bandwidth of an analog-to-digital converter (ADC). The specified chirped waveform can include a first chirped waveform during a first duration, and a second chirped waveform during a second duration. 1generating a specified chirped waveform and a specified downconversion local oscillator (LO) frequency using a digital-to-analog converter (DAC);upconverting the chirped waveform via mixing the chirped waveform with a specified upconversion LO frequency;frequency multiplying the upconverted chirped waveform to provide a chirped excitation signal for exciting the sample;receiving an emission from the sample, the emission elicited at least in part by the chirped excitation signal; anddownconverting the received emission via mixing the received emission with a signal based on the specified downconversion LO signal to provide a downconverted emission signal within the bandwidth of an analog-to-digital converter (ADC);wherein the generating the specified chirped waveform includes generating a first chirped waveform during a first duration, and a second chirped waveform during a second duration, the first and second chirped waveforms including respective bandwidths ...

MULTIDIMENSIONAL SPECTROMETER

A multidimensional spectrometer encodes frequency information into laser pulses so that a frequency insensitive detector may be used to collect data for a multi-dimensional spectrograph only from intensity information and knowledge of a modulation providing the encoding. In one embodiment the frequency encoding may be done by a conventional interferometer greatly simplifying construction of the spectrometer. 1. A multi-dimensional spectrometer comprising:a first spectral modulator producing at least one first modulated light pulse passing along a first optical path;a second spectral modulator producing at least one second modulated light pulse passing along a second optical path;a sample volume positioned at an intersection of the first and second light pulses;a detector positioned to measure an intensity of at least one of the first and second light pulses after passage through the sample volume; anda controller communicating with the first and second spectral modulator and operating to collect intensity and modulation information during a modulation of the first and second light pulses so as to permit generation of a two dimensional spectrum of a sample in the sample volume solely from the intensity and modulation information;wherein the detector provides a measure of light intensity without discriminating among light frequencies.2. The multi-dimensional spectrometer of wherein the detector is a single photo detector.3. The multi-dimensional spectrometer of wherein the first and second spectral modulators are pulse shapers.4. The multi-dimensional spectrometer of wherein the pulse shapers provide a spectrally dispersing element followed by a spectrally reconstituting element claim 3 , the spectrally dispersing element and spectrally reconstituting element positioned on either side of an electrically controlled spatial modulator.5. The multi-dimensional spectrometer of further including a processor receiving only intensity data from the detector and modulation data ...

GAS ABSORPTION SPECTROSCOPIC DEVICE AND GAS ABSORPTION SPECTROSCOPIC METHOD

A gas absorption spectrometer is provided that is capable of measuring a gas concentration and the like with high accuracy even when a measurement target gas is mixed with a gas other than the measurement target gas. A gas absorption spectrometer includes: a wavelength tunable light source; a light source control unit to change a wavelength of the light source; a gas cell to have a measurement object gas introduced thereto, the measurement object gas containing a measurement target gas and a mixed gas other than the measurement target gas; a photodetector to detect intensity of light having passed through the gas cell; a spectrum preparation unit to prepare an absorption spectrum of the measurement object gas from a change in the light intensity relative to the change in the wavelength; a physical quantity measurement unit to measure at least one of a temperature and a concentration of the measurement target gas based on an absorption spectrum of the measurement target gas; a gas concentration measurement unit to measure a concentration of the mixed gas; and a physical quantity correction unit to correct at least one of the temperature and the concentration of the measurement target gas measured by the physical quantity measurement unit based on the concentration of the mixed gas. 1. A gas absorption spectrometer , comprising:a wavelength tunable light source;a light source control unit configured to change a wavelength of light emitted from the light source;a gas cell configured to have a measurement object gas introduced thereto, the measurement object gas containing a measurement target gas and a mixed gas other than the measurement target gas;a photodetector configured to detect intensity of light emitted from the light source and having passed through the gas cell;a spectrum preparation unit configured to prepare an absorption spectrum of the measurement object gas from a change in the light intensity relative to the change in the wavelength by the light source ...

TERAHERTZ SPECTROSCOPY SYSTEM AND METHOD

A terahertz spectrometer includes: a terahertz-wave emitter and a terahertz receiver elements. The terahertz wave generated by means of generating beat frequency corresponding to the difference between two rapidly tunable continuous wave lasers. Having a difference in time between the interrogating signal and the reference signal at the receiver end side, which corresponds to intermediate frequency (IF), not centered around the baseband, i.e. zero Hertz. The offset step size of the intermediate frequency from zero Hertz is linearly correlated to the position of the interrogated object position. 128-. (canceled)29. A high-frequency spectroscopy system , the system comprising:a radiation generator for generating an inspecting radiation component and a reference radiation component of the same properties;a frequency sweeping module associated with said radiation generator for inducing frequency modulation in said inspecting and reference radiation components, said frequency modulation having a global frequency sweeping rate and a local frequency sweeping rate corresponding to a predetermined frequency and radial resolution to be obtained in a spectroscopic measurement; anda radiation receiver unit configured and operable for mixing the reference radiation component and a responding radiation component being a reflection or transmission of the inspecting radiation component from or through the sample, said receiver unit being configured and operable for determining a frequency difference between the reference and responding radiation components being mixed and utilizing said local frequency sweeping rate to identify an in-depth location, at said radial resolution in a sample, associated with said received responding signal. This invention relates to spectroscopic system and method and particularly to terahertz spectroscopy techniques.Spectroscopy is one of the main compelling applications of terahertz (THz) radiation. A typical THz Spectroscopy system includes a tunable ...

AMPLIFIER AMPLITUDE DIGITAL CONTROL FOR A MASS SPECTROMETER

Control of an amplitude of a signal applied to rods of a quadrupole is described. In one aspect, a mass spectrometer includes an amplifier circuit that causes a radio frequency (RF) signal to be applied to the rods of the quadrupole based on an amplifier RF input signal. An analog-to-digital converter (ADC) can generate a digital representation of the RF signal. A controller circuit can receive the digital representation and adjust an amplitude of the amplifier RF input signal based on differences between an amplitude of a fundamental frequency of the RF signal being different than an expected amplitude. 1. An apparatus , comprising:an amplifier circuit configured to cause a radio frequency (RF) signal to drive a quadrupole mass analyzer based on an amplifier RF input signal;an inductor coil disposed between the amplifier circuit and the quadrupole mass analyzer, and the inductor coil configured to generate the RF signal;an analog-to-digital converter (ADC) configured to generate a digital representation of the RF signal; anda controller circuit configured to receive the digital representation of the RF signal and adjust an amplitude of the amplifier RF input signal responsive to a determination that an amplitude of a fundamental frequency of the RF signal is different than an expected amplitude.2. The apparatus of claim 1 , wherein the determination that the amplitude of the fundamental frequency of the RF signal is different than the expected amplitude includes applying a digital signal processing (DSP) technique to transform the digital representation of the RF signal to a frequency domain claim 1 , and the amplitude of the fundamental frequency is identified from frequency components including harmonics of the RF signal.3. The apparatus of claim 2 , wherein the DSP technique is a discrete cosine transform (DCT).4. The apparatus of claim 1 , wherein the expected amplitude is an amplitude of the amplifier RF input signal.5. The apparatus of claim 1 , wherein the ...

Method and System for Correcting Incident Light Fluctuations in Absorption Spectroscopy

A method and system for correcting the effect of intensity fluctuations of the transmitted light in an absorption spectroscopy system used for the detection or measurement of chemical species in a medium, whereby one or more modulation bursts are imposed onto a light beam that passes through the medium. This burst signal may be obtained by modulating the bias current of a tunable diode laser, and the modulation burst signal may be optimally at the second harmonic of the modulation frequency of a wavelength modulated beam to allow usage of the same signal path processing used for the spectroscopic detection of the measurand for a second harmonic detection system. The burst signal can be controlled using a smooth window function to minimise the effects of non-linear perturbations that are inherent in tunable diode laser wavelength modulation spectroscopy systems, of optical interference fringes (etalons) and of the residual light absorption by background chemical species or the measurand at the wavelength coinciding with the modulation burst.

Material Property Determination Using Photothermal Speckle Detection

A device, and corresponding method, can include a pump light source configured to irradiate a target specimen. The device can also include a sensor configured to observe a probe speckle pattern based on light from a probe light source reflected from the target specimen. The device further may include a correlator configured to determine a material property of the target specimen by analyzing changes in images of the probe speckle pattern as a function of the irradiation with the pump light source. Advantages of the device and method can include much higher sensitivity than existing methods; the ability to use visible probe wavelengths for uncooled, low-cost visible detectors with high spatial resolution; and the ability to obtain target material properties without detecting infrared light. 1. A device comprising:a pump light source configured to irradiate a target specimen;a sensor configured to observe a probe speckle pattern based on light from a probe light source reflected from the target specimen; anda correlator configured to determine a material property of the target specimen by analyzing changes in images of the probe speckle pattern as a function of the irradiation with the pump light source.2. The device of claim 1 , wherein the material property is an absorption spectrum of the target specimen.3. The device of claim 1 , wherein the material property is a thermal diffusivity of the target specimen.4. The device of claim 1 , wherein the sensor is further configured to observe the probe speckle pattern based on light from an ultraviolet or visible probe light source reflected from the target specimen.5. The device of claim 1 , wherein the pump light source is configured to be modulated periodically.6. The device of claim 5 , wherein the pump light source is further configured to be modulated at a plurality of modulation frequencies.7. The device of claim 1 , wherein the correlator is configured to perform a frequency analysis to determine correlation of the ...

Spectroscopic Apparatus and Method

There is described an apparatus () for measuring an amount of an analyte in a mixture. In one example, the apparatus () has a laser source () for generating a frequency-modulated laser beam (). A cavity () receives the frequency-modulated laser beam () and a photodetector () obtains an intensity signal indicative of an interaction between the frequency-modulated laser beam () and the mixture. The apparatus () has a first demodulator () for producing a first demodulation signal. A frequency locking arrangement uses the first demodulation signal to lock a carrier frequency of the frequency-modulated laser beam () and a mode of the cavity () to each other. The apparatus has a second demodulator () for producing a second demodulation signal and for generating, on the basis of the second demodulation signal, an output indicative of the amount of the analyte in the mixture. Other apparatus and methods are described.

Quantum Cascade Laser (QCL) Based Gas Sensing System and Method

A system and method are disclosed for gas sensing over a wide tunable wavelength range provided by one or more quantum cascade lasers. A laser beam is generated within the wide tunable wavelength range, which is given by the sum of the wavelength ranges from the individual lasers. Gas sensing or detection is achieved by obtaining an infrared absorption spectrum for a sample contained in one or more cells having different path lengths for the laser beam. 1. A gas sensing system , comprising:at least one quantum cascade laser configured for tuning within a wavelength range and for providing a beam in the wavelength range;at least one cell for containing a gas sample, from a semiconductor processing operation, and for receiving the beam; anda detector system configured for obtaining at least one absorption spectrum for the sample by detecting the beam exiting the at least one cell, which optionally has a multipass cell.2. A method for gas sensing , comprising:providing at least one quantum cascade laser configured for tuning within a wavelength range and for providing a beam in the wavelength range;directing the beam through at least one cell containing a sample from a semiconductor processing operation; and{'sub': 2', '2', '4', '3', '4', '2', '4', '2', '6', '3', '6', '3', '8', '4', '6', '4', '8', '5', '8', '2', '2', '3', '3', '2', '3', '2', '3', '4', '4', '2', '2', '6', '3', '3', '2', '2', '2', '2', '4', '3', '2', '2', '2', '2', '2', '2', '2', '4', '2', '6', '3', '2', '2', '4', '4', '4', '4', '3', '2', '6', '3', '8', '2', '2', '2', '2', '6', '3', '4', '3', '3', '6', '3', '2', '2', '2', '4', '2, 'obtaining at least one absorption spectrum for the sample by detecting the beam exiting the at least one cell, which optionally further comprises determining concentrations of any of the following: HO, CO, CO, CH, NH, plus other hydrocarbons; fluoro-carbons: CF, CF, CF, CF, CF, CF, CF, CF; hydro-fluoro-carbons: CHF, CHF, CHF, CHF, CHF; silicon-containing: SiF, SiH, SiClH; ...

Methods and systems to analyze a gas-mixture

A system is presented. The system includes an absorption cell filled-with a gas-mixture, a mirror-cum-window comprising a first portion that acts as a first mirror and a second portion that acts as a first window, a second mirror, a plurality of radiation sources to generate a plurality of light beams directed into the absorption cell through the first window followed by reflection of the plurality of light beams between the first mirror and the second mirror to irradiate the gas-mixture resulting in generation of a plurality of transmitted light beams passing out of the absorption cell through the second window, a detector that detects at least one characteristic of the plurality of transmitted light beams resulting in generation of one or more response signals, and a processing subsystem that analyzes the gas-mixture at least based on the one or more response signals.

Methods and systems for detection and identification of concealed materials

Methods and systems for efficiently and accurately detecting and identifying concealed materials The system includes an analysis subsystem configured to process a number of pixelated images, the number of pixelated images obtained by repeatedly illuminating, through a patterning component, regions, where an electromagnetic radiation source, from a number of electromagnetic radiation sources, illuminates the patterning component, each repetition performed with a different wavelength. A number of Global pixelated images are obtained. The number of global pixelated images, after processing, constitute a vector of processed data at each pixel from a number of pixels. At each pixel, the vector of processed data is compared to a predetermined vector corresponding to a predetermined material, presence of the predetermined material being determined by the comparison.

Terahertz spectroscopy system and method

A terahertz spectrometer includes a terahertz-wave emitter and a terahertz receiver elements. The terahertz wave generated by means of generating beat frequency corresponding to the difference between two rapidly tunable continuous wave lasers. A difference in time exists between the interrogating signal and the reference signal at the receiver end side, which corresponds to intermediate frequency (IF), not centered around the baseband, i.e. zero Hertz. The offset step size of the intermediate frequency from zero Hertz is linearly correlated to the position of the interrogated object position.

VIBRATIONAL SUM FREQUENCY GENERATION USING SHAPED NEAR INFRARED LIGHT

A vibrational sum frequency generation spectroscopy system with pulse shaping is provided. The pulse shaping provides tunable NIR-Shaped light pulses based on user input parameters which may be specified to customize the system for different experimental and testing conditions or needs. 1. A vibrational sum frequency generation spectroscopy system comprising:a near infrared (NIR) light source configured to emit light pulses centered at a preset wavelength;a beam splitter disposed in a path of the emitted light and configured to split the emitted light into first light pulses and second light pulses;an optical parametric amplifier (OPA) disposed in a path of the first light pulses and configured to convert the first light pulses into a Mid-IR light pulses via difference frequency mixing;a pulse shaper disposed in a path of the second light pulses and configured to output a tunable NIR light pulses, by adjusting at least one of a number of spectral components, an amplitude and phase of the second light pulses;a processor configured to control the pulse shaper based on mode specific parameters input by a user via a user interface, the mode specific parameters are specific to a mode of operation, the mode of operation comprises symmetric and asymmetric mode, in the symmetric mode, the pulse shaper is configured to output time-symmetric pulses and in the asymmetric mode, the pulse shaper is configured to output time-asymmetric pulses;an optical system configured to combine the Mid-IR light pulses output by the OPA which has been polarized and rotated and the tunable NIR light pulses output by the pulse shaper which has been polarized and rotated;a lens configured to focus the combined light onto a target sample; anda light detector configured to detect light reflected by the target sample which has been focused, polarized and rotated.2. The vibrational sum frequency generation spectroscopy system according to claim 1 , wherein the pulse shaper comprises:a transmission ...

QCL Spectroscopy System and Applications Therefor

A spectroscopy system comprising at least two laser modules, each of the laser modules including a laser cavity, a quantum cascade gain chip for amplifying light within the laser cavity, and a tuning element for controlling a wavelength of light generated by the modules. Combining optics are used to combine the light generated by the at least two laser modules into a single beam and a sample detector detects the single beam returning from a sample. 1. A spectroscopy system comprising:at least two laser modules, each of the laser modules including a laser cavity, a quantum cascade gain chip for amplifying light within the laser cavity, and a tuning element for controlling a wavelength of light generated by the modules;combining optics for combining the light generated by the at least two laser modules into a single beam; anda sample detector for detecting the single beam returning from a sample.2. The spectroscopy system of claim 1 , further comprising three of the laser modules.3. The spectroscopy system of claim 1 , wherein the tuning element comprises a grating.4. The spectroscopy system of claim 1 , wherein the tuning element comprises a Fabry-Perot tunable filter.5. The spectroscopy system of claim 1 , further comprising projection optics for projecting the single beam to a sample.6. The spectroscopy system of claim 1 , further comprising a sighting laser and a housing with attached handle claim 1 , wherein the laser modules are contained within the housing.7. The spectroscopy system of claim 6 , wherein the system operates on 30 Watts or less.8. The spectroscopy system of claim 6 , further comprising a soil marking device for the detection of disturbed earth.9. The spectroscopy system of claim 1 , wherein the sample detector is separated from the laser modules.10. The spectroscopy system of claim 1 , further comprising retroreflectors claim 1 , wherein the single beam is projected to the retroreflectors and then returned to the sample detector.11. The ...

IMAGING METHOD AND APPARATUS

Apparatus for hyperspectral imaging, the apparatus including input optics that receive radiation reflected or radiated from a scene, a spatial modulator that spatially samples radiation received from the input optics to generate spatially sampled radiation, a spectral modulator that spectrally samples the spatially sampled radiation received from the spatial modulator to generate spectrally sampled radiation, a sensor that senses spectrally sampled radiation received from the spectral modulator and generates a corresponding output signal and at least one electronic processing device that controls the spatial and spectral modulators to cause spatial and spectral sampling to be performed, receives output signals and processes the output signals in accordance with performed spatial and spectral sampling to generate a hyperspectral image. 1) Apparatus for hyperspectral imaging , the apparatus including:a) input optics that receive radiation from a scene;b) a spatial modulator that spatially samples radiation received from the input optics to generate spatially sampled radiation;c) a spectral modulator that spectrally samples the spatially sampled radiation received from the spatial modulator to generate spectrally sampled radiation;d) a sensor that senses spectrally sampled radiation received from the spectral modulator and generates a corresponding output signal; and, i) controls the spatial and spectral modulators to cause spatial and spectral sampling to be performed;', 'ii) receives output signals; and,', 'iii) processes the output signals in accordance with performed spatial and spectral sampling to generate a hyperspectral image., 'e) at least one electronic processing device that2) Apparatus according to claim 1 , wherein apparatus includes a waveguide that receives the spatially sampled radiation from the spatial modulator and transfers this to the spectral modulator.3) Apparatus according to claim 2 , wherein the waveguide includes at least one of:a) a fibre ...

TERAHERTZ SPECTROSCOPY SYSTEM AND METHOD

A terahertz spectrometer includes: a terahertz-wave emitter and a terahertz receiver elements. The terahertz wave generated by means of generating beat frequency corresponding to the difference between two rapidly tunable continuous wave lasers. Having a difference in time between the interrogating signal and the reference signal at the receiver end side, which corresponds to intermediate frequency (IF), not centered around the baseband, i.e. zero Hertz. The offset step size of the intermediate frequency from zero Hertz is linearly correlated to the position of the interrogated object position. 1. A light source system comprising:one or more laser diodes configured and operable for radiation of predetermined properties; anda frequency modulation module associated with said one or more laser diodes, the frequency modulation module comprising at least one temperature control unit configured and operable for gradually changing an operational temperature of an active region of at least one laser diode thereby causing a substantially monotonic change in a frequency output of the laser diode; and at least one electric current control unit configured and operable for modulating an electric current through at least one of the laser diodes concurrently with said gradual changing of the operational temperature thereby inducing an additional frequency sweeping pattern in a frequency modulated output of the laser diode.2. The light source system according to claim 1 , wherein a first characteristic time scale of said monotonic change in the frequency output is longer than a second characteristic time scale of the frequency sweeping claim 1 , thereby producing frequency modulation in the form of a sequence of local changes in the frequency output during a global change corresponding to said monotonic change in the frequency output.3. A radiation transmitter unit for use in spectroscopic measurements of a sample comprising the light source system of claim 2 , wherein said one or ...

Method and Gas Analyzer for Measuring the Concentration of a Gas Component in a Sample Gas

Method and gas analyzer for measuring the concentration of a gas component in a sample gas, wherein to measure the concentration of a gas component in a sample gas, a laser diode is actuated by a current and light generated by the laser diode is guided through the sample gas to a detector, the current is simultaneously varied within periodically successive sampling intervals for the wavelength-dependent sampling of an absorption line of interest of the gas component, and the current can be additionally modulated sinusoidally based on wavelength modulation spectroscopy with a low frequency and small amplitude, such that a measuring signal generated by the detector is evaluated to form a measurement result, where to improve the measuring signal-noise ratio and achieve a much lower detection limit with the same measuring distance, the current is modulated with a high (RF) frequency in the GHz range so that no wavelength modulation occurs, and an RF modulation amplitude is selected at the maximum level using the linear control range of the laser diode where, before evaluation, the measuring signal is demodulated at the radio frequency. 110.-. (canceled)11. A method for measuring a concentration of a gas component in a sample gas via a gas analyzer , the method comprising:guiding a current (I) and light generated by a wavelength-tunable laser diode through the sample gas to a detector to actuate a wavelength-tunable laser diode;varying the current (I) in periodically successive sampling intervals for a wavelength-dependent sampling of an absorption line of interest of the gas component;modulating the current (I) sinusoidally with a predefined frequency and amplitude; anddemodulating a measuring signal generated by the detector at a modulation frequency and evaluating an obtained demodulated measuring signal to form a measurement result;wherein the modulation frequency is selected as a function of properties of the wavelength-tunable laser diode at a level which ensures ...

Method and Apparatus for the Synthesis of Electromagnetic Radiation

The invention relates to a method for the synthesis of electromagnetic radiation, wherein electromagnetic radiation having a spectrum comprising two or more spectral components is generated and phase setting of the electromagnetic radiation is performed. The invention proposes that the phase setting comprises phase shifting of the spectral components of the electromagnetic radiation, wherein the relative phase relationship of the spectral components is predeterminable. In addition, the invention relates to an apparatus for the synthesis of electromagnetic radiation, said apparatus comprising a pulsed laser ( 1 ), which generates a sequence of temporally equidistant light pulses, wherein the spectrum of the electromagnetic radiation of the pulsed laser ( 1 ) is the spectrum of an optical frequency comb, which is characterized by an offset frequency and a repetition rate. Furthermore, the apparatus has a phase setter ( 5 ), which effects phase setting of the electromagnetic radiation of the pulses laser ( 1 ). In accordance with the invention, the offset frequency of the spectral lines of the optical frequency comb is adjustable by time-proportional phase setting by means of the phase setter ( 5 ).

LASER SPECKLE REDUCTION AND PHOTO-THERMAL SPECKLE SPECTROSCOPY

A method of reducing laser speckle by reflecting an infrared laser off a rotating diffuser and coupling the diffused light into a multi-mode optical fiber. Also disclosed is a photo-thermal speckle spectroscopy device having an infrared laser, a visible laser, a foam, and a camera. The infrared and visible lasers are focused on the foam, which causes the visible laser to scatter. A camera records the speckle pattern, which shifts when the IR laser is turned on. The related method of photo-thermal speckle spectroscopy is also disclosed. 1. A method of reducing speckle , comprising:focusing an infrared (IR) laser input beam onto a rotating diffuser; andcoupling diffused laser light into a multi-mode optical fiber.2. The method of claim 1 , additionally comprising illuminating a sample with light from the multi-mode optical fiber that covers a portion of a field view of a reflecting objective claim 1 , wherein the reflected light is sent to a micro-bolometer.3. The method of claim 1 , additionally comprising illuminating a sample at a distance from the multi-mode optical fiber with light from the multi-mode optical fiber.4. A photo-thermal speckle spectroscopy device claim 1 , comprising:an infrared (IR) laser that is toggled on and off;a visible laser that is always on;a substrate, wherein the substrate comprises an analyte to be tested; anda camera;wherein the IR laser and the visible laser are directed to the substrate causing the visible laser to scatter, wherein the camera records a speckle pattern, and wherein the speckle pattern changes when the IR laser is turned on.5. The photo-thermal speckle spectroscopy device of claim 4 , wherein the substrate is a foam.6. The photo-thermal speckle spectroscopy device of claim 4 , wherein the substrate is a polyethylene foam.7. The photo-thermal speckle spectroscopy device of claim 4 , wherein the substrate is a meta-material or other structure that is engineered to suppress IR absorption.8. The photo-thermal speckle ...

Real-Time Programmable ICE and Applications in Optical Measurements

A system and method are disclosed for configuring an integrated computational element (ICE) to measure a property of a sample of interest. The system includes an illumination source to provide a sample light which is reflected from or transmitted through a sample. A dispersive element disperses the sample light into wavelength portions. An intensity modulation device having an array of electronically controllable modulation elements is disclosed that forms a pattern which modulates the dispersed sample light. Collection optics focuses the modulated sample light on a detector, which generates a signal that correlates to a property of the sample. The electronically controllable modulation elements can be readily altered to conform to a different measurable property of a sample of interest as desired. 1. An optical system for the measurement of properties of a fluid sample from a wellbore in an earthen formation , the optical system comprising:a sensor package positioned in the wellbore, the sensor package containing a sample containment area to receive the fluid sample;an illumination source to direct an illumination light at the fluid sample and to provide a sample light in response to illumination of the fluid sample by the illumination light;a dispersive element to disperse the sample light into wavelength portions;an intensity modulation device comprising an array of modulation elements electronically controllable to provide a modulated sample light including a selected portion of the dispersed sample light;a signal detector; andcollection optics to direct the modulated sample light to the detector.2. The optical system of wherein the modulation elements are electronically controllable to provide a complementary modulated sample light including a second selected portion of the dispersed sample light.3. The optical system of wherein a difference between a sample light pattern and a complementary sample light pattern is a linear regression vector associated with a ...

SYSTEMS AND METHODS FOR CORRECTION OF FREQUENCY SPECTRUM IN DUAL COMB SPECTROSCOPY

A method for correcting frequency offset in a dual comb spectroscopy system is provided. The method includes causing a first laser (L1) generator to transmit L1 pulses at a repetition rate of a first frequency and causing a second laser (L2) generator to transmit L2 pulses at a repetition rate of a second frequency. The method also includes interrogating a reference material using a combination of the L1 pulses and the L2 pulses and capturing reference cell pulses. The method further includes interrogating a material of interest using the L1 pulses and capturing material of interest pulses. The method includes determining a frequency jitter based on the captured reference cell pulses and the combination of the captured material of interest pulses and the L2 pulses. 1. A method for correcting frequency offset in a dual comb spectroscopy system , said method comprising:causing a first laser (L1) generator to transmit L1 pulses at a repetition rate of a first frequency;causing a second laser (L2) generator to transmit L2 pulses at a repetition rate of a second frequency, the second frequency different from the first frequency;interrogating a reference material using a combination of a first portion of the L1 pulses and a first portion of the L2 pulses;capturing reference cell pulses that include the combination of the first portion of the L1 pulses and the first portion of the L2 pulses that interrogated the reference material;interrogating a material of interest using a second portion of the L1 pulses;capturing material of interest pulses that include the second portion of the L1 pulses that interrogated the material of interest; anddetermining a frequency jitter based on the captured reference cell pulses and the combination of the captured material of interest pulses and a second portion of the L2 pulses.2. The method of claim 1 , wherein interrogating the material of interest includes interrogating the material of interest using the second portion of the power of ...

TERAHERTZ TIME-DOMAIN SPECTROSCOPY SYSTEM

The present application relates to a terahertz time-domain spectroscopy system. In this terahertz time-domain spectroscopy system, the femtosecond laser light radiated by the femtosecond laser is collimated by a first diaphragm, and then is split by a beam splitter into a pump light and a probe light. The pump light passes through the first light path module to generate a terahertz pulse, and the probe light passes through the first light path module to generate a linear polarization probe light having the same optical distance as that of the pump light. The linear polarization probe light and the terahertz pulse are combined by a beam combiner to obtain a light beam to be detected carrying the terahertz pulse information. Two electro-optical crystals with the same thickness are used in a detection device simultaneously. Changing the crystal axis angle of the two electro-optical crystals, there is a phase compensation to the two components o light and e light of the probe light, so as to realize linear detection to high power terahertz pulse and improve measurement accuracy. 1. A terahertz time-domain spectroscopy system , comprising:a femtosecond laser that radiates femtosecond laser light;a first diaphragm that collimates the femtosecond laser light;a beam splitter that splits the femtosecond laser light into a pump light a probe light;a first light path module;a second light path module,wherein the pump light generates a terahertz pulse by the first light path module; the probe light generates a linear polarization probe light having the same optical distance as that of the pump light by the second light path module,a beam combiner that combines the probe light and the terahertz pulse to produce a light beam to be detected carrying the terahertz pulse information;a detection device configured to detect the light beam to be detected, in the propagation direction of the light beam to be detected, the detection device comprises a first electro-optical crystal, a ...

SPECTRAL IMAGING OF A SAMPLE USING A PLURALITY OF DISCRETE MID-INFRARED WAVELENGTHS

Spectrally analyzing an unknown sample (A) includes (i) providing a spatially homogeneous region (B) of the unknown sample (A); (ii) directing a plurality of interrogation beams () at the spatially homogeneous region (B) with a laser source (), (iii) acquiring a separate output image () while the unknown sample (A) is illuminated by each of the interrogation beams () with an image sensor (A); and (iv) analyzing less than fifty output images () to analyze whether a characteristic is present in the unknown sample (A) with a control system () that includes a processor. Each of the interrogation beams () is nominally monochromatic and has a different interrogation wavelength that is in the mid-infrared spectral range. 1. A method for spectrally analyzing an unknown sample , the method comprising:providing a spatially homogeneous region of the unknown sample;directing a plurality of interrogation beams at the spatially homogeneous region with a laser source, each of the interrogation beams being nominally monochromatic and having a different interrogation wavelength that is in the mid-infrared spectral range;acquiring a separate output image of the unknown sample while the unknown sample is illuminated by each of the interrogation beams with an image sensor that senses light in the mid-infrared spectral region; andanalyzing less than fifty output images to analyze whether a characteristic is present in the unknown sample with a control system that includes a processor.2. The method of wherein analyzing includes analyzing less than thirty output images to analyze whether the characteristic is present in the unknown sample with the control system.3. The method of wherein analyzing includes analyzing less than twenty output images to analyze whether the characteristic is present in the unknown sample with the control system.4. The method of further comprising analyzing a known sample having the characteristic to identify a plurality of diagnostic spectral features claim 1 , ...

Derivative ratio test of fluid sampling cleanup

A method for performing a formation fluid test in a borehole penetrating a subsurface formation includes disposing a fluid tester in the borehole, extracting a sample of fluid from the subsurface formation using the fluid tester, and analyzing the sample using the fluid tester to provide test data for a process used to analyze the sample. The method also includes fitting an equation to the test data and calculating a ratio of a first derivative of the equation to a second derivative of the equation. The method further includes continuing to extract the sample from the subsurface formation in response to the ratio indicating a clean sample will be forthcoming and terminating the extracting of the sample from the subsurface formation in response to the ratio indicating a clean sample will not be forthcoming.

Systems and Methods for 4-D Hyperspectral Imaging

Systems and methods for hyperspectral imaging are described. In one implementation, a hyperspectral imaging system includes a sample holder configured to hold a sample, an illumination system, and a detection system. The illumination system includes a light source configured to emit excitation light having one or more wavelengths and a diffractive element. The illumination system is configured to structure the excitation light into a predetermined two-dimensional pattern at a conjugate plane of a focal plane in the sample, spectrally disperse the structured excitation light in a first lateral direction, and illuminate the sample in an excitation pattern with the one or more wavelengths dispersed in the first lateral direction. 1. A hyperspectral imaging system comprising:a sample holder configured to hold a sample;a light source configured to emit excitation light having one or more wavelengths;a two-dimensional (2-D) imaging array; and a first element comprising a first dispersive element or a first diffractive element; and', 'a second element comprising a second dispersive element or a second diffractive element;, 'an optical system comprisingwherein the optical system is configured to (i) structure the excitation light, using the first element, into a spectrally dispersed two-dimensional excitation pattern at a focal plane in the sample or a conjugate plane of the focal plane; (ii) use the excitation pattern to illuminate the sample with the one or more wavelengths dispersed along a first direction within the focal plane; (iii) collect, from the sample, emission light; (iv) spectrally disperse, using the second element, the collected emission light; and (v) provide the collected emission light in-focus to the imaging array such that the collected emission light is spectrally dispersed along a second direction.2. The hyperspectral imaging system of claim 1 , wherein the first element is configured to modulate a phase of the excitation light.3. The hyperspectral ...

Method and device for determining gas component inside a transparent container

A device for non-invasively determining existence of a gas component of interest inside a determination space of a glass unit comprises a laser beam emitting unit comprising a laser source for emitting laser beam towards said measuring space and detecting unit comprising a detector for detecting transmission of said emitted laser beams travelled through said space. The device is configured to measure in a calibration mode locations of at least one reference peak of at least same gas component as to the determined inside the determination space. The emitted laser beam is configured to travel through a calibration space having at least the gas component of interest, and the detecting means is configured essentially to detect or image said beam transmitted through said calibration space. The device is also configured to be moved so to receive said determination space between the laser beam emitting unit and detecting unit for a determining purpose of the existence of the interest gas component inside said determination space. 1. A device for non-invasively determining existence of a gas component of interest inside a determination space of a glass unit , wherein the device comprises:a laser beam emitting unit comprising a laser source for emitting laser beam towards said determination space, a detecting unit comprising a detector for detecting transmission of said emitted laser beam travelled through said determination space, and a calibration mode, whereinthe device is configured to measure in the calibration mode locations of at least one reference peak of at least a same gas component as to be determined inside the determination space, wherein said emitted laser beam is configured to travel through a calibration space having at least the gas component of interest, and wherein the detecting means is configured essentially to detect or image said beam transmitted through said calibration space, andsaid device is configured to be moved so to receive said determination ...

Rapid temperature measurement by wavelength modulation spectroscopy

Aspects of the present disclosure describe rapid temperature measurement by wavelength modulation spectroscopy (WMS) that determines gas temperature from 2ƒ signals from two absorption lines by WMS methodologies even when the gas concentration is sufficiently high to saturate optical absorptions. In sharp contrast to the prior art, rapid temperature measurement by WMS according to aspects of the present disclosure employs both a 2ƒ signal ratio and gas concentration determined from the 2ƒ signal.