ФОКУСИРОВКА ЛАЗЕРНОГО ИМПУЛЬСА

Изобретение относится к области лазерной техники и касается системы формирования лазерного излучения. Система включает в себя источник импульсного лазерного излучения, оптические элементы, содержащие фокусирующий объектив и выполненные с возможностью изменения длительности лазерных импульсов, устройство контроля, предназначенное для измерения длительности лазерных импульсов и выявления изменения длительности импульса, и управляющий компьютер. Компьютер выполнен с возможностью приема значений длительности импульса, определения параметров лазера, которые компенсируют изменение длительности импульса, и управления источником лазерного излучения в соответствии с одним или более параметров лазера. Устройство контроля выполнено с возможностью соединения с фокусирующим объективом или расположения внутри фокусирующего объектива. Технический результат заключается в увеличении точности настройки длительности лазерных импульсов. 2 н. и 14 з.п. ф-лы, 5 ил.

ФОКУСИРОВКА ЛАЗЕРНОГО ИМПУЛЬСА

Селектор фемтосекундных импульсов на основе динамического делителя частоты

Полезная модель относится к области волоконной оптики и лазерных технологий, а именно к устройствам для деления частоты следования оптических импульсов в волоконных лазерах ультракоротких импульсов. Техническим результатом полезной модели является обеспечение возможности настройки параметров управляющего сигнала: коэффициента деления, длительности импульса и времени задержки, в устройстве деления частоты следования оптических ультракоротких импульсов. Селектор фемтосекундных импульсов на основе динамического делителя частоты следования импульсов в волоконном лазере содержит волоконно-оптический разветвитель, акустооптический модулятор (АОМ), фотоприёмное устройство (ФПУ), предделитель, микроконтроллер и драйвер АОМ. 10 ил.

Modular aufgebauter, gepulster Mehrwellenlängen-Festkörperlaser für medizinische Therapieverfahren

ERZEUGUNG VON DUNKELIMPULSEN

LASERVORRICHTUNG, MESSVORRICHTUNG UND MESSVERFAHREN

Es werden eine Laservorrichtung 110, eine Messvorrichtung 100 und ein Messverfahren geschaffen, wobei die Laservorrichtung 110 einen frequenzmodulierten Laserstrahl mit mehreren Moden ausgibt und Folgendes enthält: einen optischen Hohlraum, der ein Verstärkungsmedium 114 zum Verstärken eines einzugebenden Lichts und einen optischen SSB-Modulator 30 zum Verschieben einer Frequenz des Lichts, das durch das Verstärkungsmedium verstärkt wurde, aufweist; und einen Steuerteil 50, der den optischen SSB-Modulator 30 steuert, um eine Frequenz von Licht, das in den optischen SSB-Modulator 30 eingegeben werden soll, zu verschieben.

ANORDNUNG UND VERFAHREN ZUR SCHNELLEN UMSCHALTUNG ZWISCHEN VERSCHIEDENEN WELLENLAENGEN EINES LASERS.

Dauerstrich- und Ultrakurzplus-Polymerlaser

Dauerstrich-Laser a) mit einem Laser-Resonator; b) mit einer Schicht (LD) eines organischen Festkörpers als aktives Medium des Lasers, das mindestens teilweise im Laser-Resonator positioniert ist; c) mit einer Dauerstrich-Pumplichtquelle (PL), deren Strahlung zur Erzeugung einer Besetzungsinversion in das aktive Medium (LD) fokussiert wird; und d) mit einer Einrichtung (M) zum Rotieren des aktiven Mediums (LD) in der Ebene der Schicht und zum Verfahren senkrecht zur Achse der Rotation; e) wobei die Rotationsgeschwindigkeit derart gewählt ist, dass der Laser im Dauerstrichbetrieb kohärente Strahlung aussendet; f) wobei das aktive Medium (LD) gegen die optische Achse des Laser-Resonators im Brewster-Winkel verkippt ist; g) wobei der Laser-Resonator derart ausgebildet ist, dass er eine gefaltete Konfiguration mit einem Kompensationswinkel (Θ) aufweist; h) wobei die Dicke des aktiven Mediums (LD) höchstens 200 μm, vorzugsweise höchstens 100 μm, vorzugsweise höchstens 50 μm beträgt; i) wobei ...

Abstimmbare optische Anordnung

Optischer Sender oder Verstaerker zur Projektion eines phasenmodulierenden Objektes

LICHTQUELLE MIT VARIABLER WELLENLÄNGE

Fluid decontamination apparatus and method

A LASER

APPARATUS FOR MEASURING REFLECTIVITIES OF RESONATOR FACETS OF SEMICONDUCTOR LASER

Optical Amplifiers

TUNABLE DEMULTIPLEXER AND TUNABLE LASER WITH OPTICAL DEFLECTOR

MONO MODE TUNABLE ONE SOURCE OF LASER

LASER MATRIX IN FORM OF A MICROCHIP.

WAVELENGTH TUNABLE RESONATOR WITH A PRISM

Apparatus for the generation of variable duration laser pulses

EXTERNAL CAVITY SEMICONDUCTOR LASER SYSTEM

LASER PULSE FOCUSING

In certain embodiments, a system (10) comprises a laser source (20), one or more optical elements (24), a monitoring device (28), and a control computer (30). The laser source (20) emits one or more laser pulses. The optical elements (24) change a pulse length of the laser pulses, and the monitoring device (28) measures the pulse length of the laser pulses to detect the change in the pulse length. The control computer (30) receives the measured pulse length from the monitoring device (28), determines one or more laser parameters that compensate for the change in the pulse length, and controls the laser source (20) according to the laser parameters.

NARROW BAND EXCIMER LASER APPARATUS

A narrow band excimer laser which includes a polarizer for linearly polarizing an oscillation laser beam. The polarizer also includes a birefringence filter which forms the oscillation laser beam into a narrow band.

LASER DEVICE

Anordnung zur Aussendung modulierter, nach dem Laserprinzip erzeugter Strahlung

VERFAHREN ZUM BOHREN VON WERKSTUECKEN MITTELS LASERSTRAHLEN UND ANORDNUNG ZUR DURCHFUEHRUNG DES VERFAHRENS.

LASER-OSZILLATOR-VERSTAERKER-KOMBINATION ZUR ERZEUGUNG DES GRUNDMODUS.

All-fiber laser system and method for generating high-energy rectangular pulse

Tunable optical device.

AN ELECTROMAGNETIC SWITCH BEAM FOR LASER RESONATORS

SENSOR HAS NETWORK OF BRAGG PHOTOINSCRIT HAS SIGNAL POSITIVE RATIO ON NOISE

RESONATEUR OPTIQUE SELECTIF EN ANNEAU

RESONATEUR SELECTIF EN ANNEAU. CE RESONATEUR COMPREND UN MOYEN DE POLARISATION RECTILIGNE, DEUX LAMES DEMI-ONDE ET UNE SUBSTANCE OPTIQUE INTERCALEE ENTRE LES DEUX LAMES. APPLICATION AUX LASERS ET AUX FILTRES DE FREQUENCE.

LASER A PLUSIEURS LONGUEURS D'ONDE UTILISANT UNE ROUE TOURNANTE MUNIE D'OUVERTURES

LASER A PLUSIEURS LONGUEURS D'ONDE. UN TEL LASER COMPREND UN MILIEU AMPLIFICATEUR 2 DISPOSE DANS UN RESONATEUR CONSTITUE PAR UN PREMIER REFLECTEUR 6 ET UN SECOND REFLECTEUR DISPERSIF 8 DU GENRE RESEAU DE DIFFRACTION, ET IL EST CARACTERISE EN CE QU'IL COMPREND EN OUTRE, INTERCALE ENTRE LEDIT MILIEU AMPLIFICATEUR ET LEDIT SECOND REFLECTEUR DISPERSIF, UNE ROUE TOURNANTE 14 COMPRENANT AU MOINS DEUX FENTES 20, 20 EN FORME DE PORTIONS DE CERCLES CONCENTRIQUES, CES FENTES DEFINISSANT AUTANT DE TRAJETS DIFFERENTS 10, 10 POUR LE FAISCEAU LUMINEUX DANS LE RESONATEUR ET AUTANT D'ANGLES D'INCIDENCE TH1, TH2 DIFFERENTS SUR LE REFLECTEUR DISPERSIF. APPLICATION POUR LA TELEDETECTION DE POLLUANTS ATMOSPHERIQUES.

Générateur de faisceau laser.

Générateur de faisceaux laser à puissance instantanément ajustable. Selon l'invention, l'élément actif (13) du générateur est associé à un système optique comprenant un miroir sphérique (16) et une lentille (17) et cette dernière est mobile pour compenser la perturbation d'origine thermique introduite dans le système optique par l'élément actif (13).

Multiple wavelength laser construction - has lenses on rotating wheel sequentially altering incidence of beam from amplifier

LASER GENERATOR

Selective optical ring resonator - includes active optical component in path between three mirrors and half-wave plates

SAFETY DEVICE Of a LASER RESONATOR

HIGH REPETITION RATE UV EXCIMER LASER

The invention relates to an High Repetition Rate UV Excimer Laser (10), which includes a source of a laser beam and one or more windows (16, 18) which include magnesium fluoride. Another aspect of the invention relates to an excimer laser which includes a source of a laser beam, one or more windows which include magnesium fluoride and a source for annealing the one or more windows. Another aspect of the invention relates to a method of producing a predetermined narrow width laser beam. © KIPO & WIPO 2007 ...

LASER GENERATOR HAS REDUCED EMISSION SPECTRA

Laser device for manufacturing printing plates

The laser device according to the invention for manufacturing printing formes is intended for use mainly in the graphic industries and comprises firstly a system of synchronous scanning of a pattern-master and of a forme material, secondly an optoelectronic reading unit 16 and a generator 17 of raster impulses optically interconnected with the system of synchronous scanning, and electrically connected to an electronic circuit providing for generation of sequence of signals controlling parameters of the laser radiation, which allows to obtain, during the time of a single technological cycle, both the line and half-tone structures on the forme material, said electronic circuit comprising: a line channel, a raster channel connected in parallel therewith, a raster-line commutator device 28 intended for switching automatically the line and raster channels, and a unit 31 of fixation of boundaries of half- tone images, said unit 31 being kinematically interconnected with the system of synchronous ...

TUNABLE DUAL FREQUENCY LASER CAVITY AND METHOD FOR ADJUSTING THE FREQUENCY DIFFERENCE BETWEEN AN ORDINARY WAVE AND AN EXTRAORDINARY WAVE OF A DUAL FREQUENCY LASER

The present invention relates to an emission cavity of a dual frequency laser (L), of the type comprising an input mirror (1) and at least one laser crystal (5), said laser crystal (5) being capable of simultaneously emitting an ordinary laser wave (O0) and an extraordinary laser wave (Oe) at different frequencies when the laser crystal is excited by at least one pumping light beam (FP1, FP2) introduced by the input mirror. The invention is characterized in that it includes an optical coupling device (CO) positioned at an output of the cavity and comprising at least one reflecting volume Bragg grating (3, 4), said one or more Bragg gratings (3, 4) having a pitch chosen so as to partially reflect a resonant wavelength located in the spectral gain bandwidth of the laser wave (O0, Oe) on the optical path of which said grating is placed.

LASER SOURCE UNIT AND OPTICAL ACOUSTIC IMAGE GENERATION DEVICE

In the present invention, a Q-switched pulse oscillation is acquired with a simple configuration by continuously switching a plurality of wavelengths in a laser source unit. The laser source unit (13) emits a pulsed laser with multiple mutually different wavelengths. A flash lamp (52) irradiates a laser rod (51) with excitation light. A pair of mirrors (53, 54) is opposite each other having the laser rod (51) sandwiched therebetween. An optical resonator is composed of the pair of mirrors (53, 54). A wavelength selection means (56) controls the wavelength of the light resonated in the optical resonator so that it is one of the plurality of wavelengths to be emitted by the laser source unit (13). A drive means (57) drives the wavelength selection means (56) such that the optical resonator performs the Q-switched pulse oscillation.

LASER FOR GENERATING MULTIPLE WAVELENGTHS

A laser system comprising: a first reflector and a second reflector defining a first resonator cavity; a third reflector defining a second resonator cavity with the first reflector; a laser material disposed such that it is located in both the first and the second resonator cavities, the laser material being capable of generating at least a first and a second wavelength of laser light when pumped by pump radiation from a pump source located external to the first and second resonator cavities; wherein the first reflector is adapted to reflect the first wavelength of laser light into the first resonator cavity and the third reflector is adapted to reflect the second wavelength of laser light into the second resonator cavity.

CONTINUOUS-WAVE SOLID-STATE LASER COMPRISING A DYE IN A THIN ROTATING LAYER

Disclosed is a laser comprising a thin polymer dye layer as an active medium. Said layer is placed in a sandwich structure between two CD blanks or DVD blanks, whereby a laser disk (LD) is created. The inventive laser comprises a folded laser resonator and is pumped by a continuous-wave pump light source (PL). The laser disk is tilted at the Brewster angle towards the optical axis of the laser resonator. The laser disk is rotated quickly with the aid of a motor (M) in order to convey all unwanted photoproducts of the dyes as well as dyes that are in long-lived, inactive states out of the inversion volume of the active medium so as to maintain the laser activity, thus allowing the laser to be operated in a continuous-wave mode. The disclosed laser is configured as a continuous-wave solid-state dye laser which can be continuously adjusted across a wide range by means of a double-refractive crystal (BRF).

DECONTAMINATION APPARATUS AND METHOD

A decontamination apparatus comprises a laser having an optical resonance cavity disposed between a first reflector and a second reflector, and comprises means to pass a fluid for decontamination through at least a first region of the optical resonance cavity.

METHOD AND APPARATUS FOR CONTROLLING EXTERNAL CAVITY LASER

Provided herein are a method and apparatus for controlling the wavelength of an external-cavity wavelength-tunable laser. The reflectivity or transmittance characteristics of a wavelength depend on the phase difference between light reflected by a wavelength-tunable filter and parasitic reflective light. Thus, when the temperature of a module and current applied to a phase control electrode and an external reflector are changed, the characteristics are changed in a periodic manner. The present disclosure relates to a wavelength control algorithm of determining combinations of these parameters to set conditions having optimum chirping characteristics at a desired wavelength.

Tunable demultiplexer and tunable laser with optical deflector

Provided are a tunable demultiplexer and a tunable laser, having an optical deflector in which a refractive index of a core layer of a deflection pattern region having a predetermined shape varies in response to an external electrical signal so that the optical deflector deflects incident light in the radial direction.

Frequency doubled laser having power triggered optimization and regulation

A nonlinear optical device having a yttrium-aluminum-garnet or yttrium-lithium-fluoride laser rod for producing radiation of a fundamental wavelength, a first mirror located in front of the laser rod along the longitudinal axis of the laser rod reflective of the radiation of the fundamental wavelength but transmissive of radiation of a desired harmonic wavelength, a second mirror located to the rear of the laser rod along the longitudinal axis of the laser rod reflective of radiation of the fundamental wavelength, a phase matched crystal harmonic wavelength generator mounted on a movable platform driven by a motor arranged between the front mirror and the laser rod responsive to radiation of the fundamental wavelength for generating radiation of the desired harmonic wavelength, an output sensor arranged in front of the first mirror for generating a signal indicative of the output power of the laser rod, a beamsplitter for directing a portion of the laser rod output power to the output sensor ...

Phase plate or spiral phase wheel driven linear frequency chirped laser

Frequency modulated radar transmitters with a repetitive linear increase in frequency with time, referred to as "frequency chirps", are required for many radar applications. The present invention provides a simple way of obtaining such a chirped frequency modulation for a laser radar transmitter or the like. The principle is to translate an optical wedge in the direction of its wedge gradient at constant velocity across the optical path of a laser resonator. The resulting increase or decrease in the effective optical length of the resonator causes frequency chips. In a first embodiment of the present invention, a rotating phase plate on the face of a rotating wheel with the added phase varying linearly with angular position around the wheel is placed within a laser's resonator cavity to tune the optical pathlength of the cavity and thereby the longitudinal mode of the resonator to produce the chirp. This embodiment can be used in either a reflective or a transmissive mode. In a second embodiment ...

Laser ultrasonics-based material analysis system and method utilizing optimum triggering time

A method and apparatus for interferometrically monitoring a target to determine, in accordance with predetermined criteria, an occurrence of a period of time that is optimum for obtaining a data point. In response to detecting such a period an impulse source, such as an impulse laser (14), is triggered to launch an elastic wave within the target so that a data point can be obtained.

Laser apparatus

The laser apparatus according to the present invention comprises an output mirror for reflecting a portion of a laser beam and transmitting therethrough a remaining thereof; a full reflection mirror located at a position opposite to this output mirror for completely reflecting a laser beam and changing the curvature; a laser medium provided between the output mirror and the full reflection mirror for causing induced emission; an aperture means for deciding a beam mode of a laser beam generated between the output mirror and the full reflection mirror and changing the aperture diameter; and a converging means for converging an outgoing laser beam from the output mirror and changing a distance from the output mirror according to a machining path; and the laser apparatus changes a curvature of the full reflection mirror and also changes a diameter of the aperture means.

Laser with selectable wavelength

In order to enable adjustment of the output wavelength of a laser, there is provided a laser comprising a laser-active material (100), which is excitable at not less than two laser wavelengths to emit laser beams with a gain, said gain being different at the two laser wavelengths, a resonator comprising two end mirrors (102, 110; 130, 132), in which resonator the laser-active material (100) is arranged and which resonator is adapted, with respect to its resonance conditions, to the laser wavelength having the lower gain, wherein one of said end mirrors (110, 132) is partially transmissive for radiation at said laser wavelengths, an output mirror (116), which is partially transmissive for said laser wavelengths and is arranged following the partially transmissive end mirror (110, 132) in the optical path, an optical element (112, 120), which is arranged between the partially transmissive end mirror (110, 132) and the output mirror (116), on which radiation is incident at said laser wavelengths ...

Single frequency adapter

Tunable solid state laser with high wavelength selectivity over a preselected wavelength range

A tunable solid state laser for producing a laser emission at any desired low or high laser gain transition in a predetermined range of wavelengths is disclosed. The tunable solid state laser comprises: a laser cavity defined by a first reflective element and an output coupler reflective element to form a reflective path therebetween; a laser crystal disposed in the laser cavity; means for optically exciting the laser crystal to produce a laser emission in the predetermined range of wavelengths; a tunable element disposed in the laser cavity between the laser crystal and one of the reflective elements for tuning the laser emission to any desired laser transition in the predetermined range of wavelengths; and a plurality of optical plates oriented at Brewster's angle in the reflective path in the laser cavity for suppressing oscillation of undesired wavelengths within the laser cavity, the optical plates being transparent to the laser emission over the predetermined range of wavelengths.

Article comprising an optical fiber laser

An article, such as an optical communication system, which includes a laser formed in an optical waveguide or optical fiber having a rare-earth-doped core or core portion. In one embodiment, the optical resonant cavity of the laser is at least partially defined by a distributed Bragg reflector (10, 20) formed in a portion of the core. In contrast to the prior art, the length of the optical resonant cavity is about 5 cm or less. ...

DUAL FREQUENCY LASER LITHOTRIPTER

Method and apparatus are provided for laser lithotripsy by subjecting calcified matter in the mammalian body, especially the human body, to two spatially and temporally overlapping pulsed laser light beams in the 300-450 and 600-900 nanometer wavelength ranges. In a first embodiment, the two laser light beams are formed by a tunable laser (19) in combination with a frequency doubling crystal (6). In a second embodiment, each of the two laser light beams is formed by an independent tunable laser (15 and 16) and the beams are then combined by mirror (12). In both embodiments, a front surface mirror (7) is employed to direct the laser beams into an endoscopic delivery system (8).

Emerald laser

Vorrichtung und Verfahren zum Verstärken von Lichtimpulsen

Vorrichtung (1, 11) zum Verstärken von Lichtimpulsen (2, 12), mit einem Strecker (4, 14), der die Lichtimpulse (2, 12) zeitlich streckt, wenigstens einem Verstärker (5, 15), der die gestreckten Lichtimpulse (2, 12) verstärkt, und einem Kompressor (6, 16), der die gestreckten und verstärkten Lichtimpulse (2, 12) rekomprimiert, wobei der Strecker (4, 14) und der Kompressor (6, 16) dispersive Elemente mit im Wesentlichen entgegengesetzt gleicher Dispersion sind, dadurch gekennzeichnet, dass die Dispersion des Verstärkers (5, 15), die Dispersion weiterer optischer Elemente der Vorrichtung (1) und/oder die Fehlanpassung der Dispersion von Strecker (4, 14) und Kompressor (6, 16) durch wenigstens ein zusätzliches Element (17) variabler Dispersion zumindest teilweise kompensiert sind.

Pulsshaper und Infrarotlaser mit Pulsshaper

Pulsshaper zur Kompensation von Gruppenlaufzeiteffekten, aufweisend: einen ersten Keil (11) und einen zweiten Keil (12) mit jeweils zwei planar ausgebildeten Seitenflächen (13), die unter einem spitzen Winkel zusammenlaufen, wobei der erste Keil (11) und der zweite Keil (12) aus einem Material mit einer Absorption von weniger als 10% je cm für elektromagnetische Strahlung im mittleren infraroten Spektralbereich bestehen und sich die optische Dispersion des Materials des ersten Keils (11) von der optischen Dispersion des Materials des zweiten Keils (12) unterscheidet, und wobei die Keile (11, 12) derart zueinander angeordnet sind, dass die Spitzen der Keile (11, 12) in entgegensetzte Richtungen zeigen und sich die einander zugewandten Seitenflächen (13) der Keile (11, 12) mindestens teilweise gegenüberstehen.

MULTIPLE-WAVELENGTH LASER USING A ROTATING APERTURED WHEEL

Gepulste Laserquellen

Frequenzkammquelle (800), zur Erzeugung eines Frequenzkamms, wobei die Frequenzkammquelle umfasst:einen modengekoppelten Faseroszillator (801) mit einer resonanten Kavität, die eine optische Faser mit einer Länge L aufweist, und mit reflektierenden Elementen an den Enden, wobei die resonante Kavität mehrere optische Moden unterstützt und der modengekoppelte Faseroszillator (801) die mehreren optischen Moden modenkoppelt,um ein modengekoppeltes optisches Signal zu erzeugen, wobei das modengekoppelte optische Signal Frequenzkomponenten des Kamms aufweist, die um einen Frequenzabstand fgetrennt und von Null um eine Trägereinhüllende-Offset-Frequenz fversetzt sind;ein Rückkopplungssystem (819) zum Steuern und Stabilisieren der Offset-Frequenz, f, und des Frequenzabstands fdes modengekoppelten Faseroszillators (801) in Reaktion auf ein Rückkopplungssignal, das für eine Schwebungssignalfrequenz repräsentativ ist;eine stark nicht lineare optische Faser (805), die dem modengekoppelten Faseroszillator ...

VORRICHTUNG ZUR MESSUNG DER REFLEXIONSVERMOEGEN VON RESONATORFACETTEN VON HALBLEITERLASERN

Laser resonator architecture

The invention relates to a laser resonator 5 comprises at least one output coupler 10 a; at least one end reflector 10b; a retroreflector 15; a telescope 20; a gain medium 25 and the telescope 20 is a common telescope 20 provided in a beam path between the retroreflector 15 and both the end reflector 10b and the output coupler 10a. The end reflector 10b may comprise an end mirror or Porro prism. The retro reflector may be a corner cube. Resonator telescope geometry may be optimised for low boresight sensitivity to telescope focus. The arrangement may also be end pumped via a polariser beam splitter which is operable as a Q-switch (Figure 2).

Tunable optical arrangement

A prism 3b having a variable refractive index is used as a tuning means for controlling the angle of incidence of a light beam directed onto a grating 5b. The refractive index may be vaned by carrier injection, carrier depletion, the use of a BRAQWET(Blockaded Reservoir And Quantum-Well Electron-Transfer Structures), the quantum confinement Stark effect, or temperature tuning. The device may form part of a tunable filter. ...

Improvements in or relating to lasers or masers

... 1,068,052. Modulating laser and maser radiation. SIEMENS A.G. April 13, 1964 [April 11, 1963; April 16, 1963; May 22, 1963], No. 15099/64. Heading H1C. The oscillatory radiation path in a laser or maser extends through a modulator which is controllable so that variable proportions of the laser or maser radiation may be retained in the radiation path and picked off from the path. In Fig. 1, laser element 1 lies in a resonant cavity 2, 21, partial reflector 2 forming with a partial reflector 4 a further cavity containing a control element 5, the refractive index is varied by means of a modulating electric field. The assembly 2, 4, 5 forms a variable reflectivity interference mirror allowing the proportions of radiation picked off and retained to be varied. The assembly is adjusted so that a mean beam intensity is picked off in the absence of a modulating field, or element 5 is D.C. biased. In a push-pull system (Fig. 3, not shown) a similar interference mirror is arranged at the ...

COMPENSATION OF THERMALOPTICAL EFFECTS

DIODE LASER SYSTEM WITH EXTERNAL RESONATOR

OPTICAL RESONATORS WITH ORTHOGONAL POLARIZED MODES

Method of making high repetition rate excimer laser crystal optics and uvless than200nm transmitting optical floride crystal

MICROCHIP LASER

CR-DOPED SCANDIUM BORATE LASER

Barium fluoride high repetition rate uv excimer laser

CR-DOPED SCANDIUM BORATE LASER

Cr-DOPED SCANDIUM BORATE LASER A broadly wavelength-tunable laser is provided which comprises as the laser medium a single crystal of MBO3:Cr3+, where M is selected from the group of Sc, In and Lu. The laser may be operated over a broad temperature range from cryogenic temperatures to elevated temperatures. Emission is in a spectral range from red to infrared, and the laser is useful in the fields of defense, communications, isotope separation, photochemistry, etc.

EMERALD LASER

EMERALD LASER A broadly wavelength-tunable laser is provided which comprises as the laser medium a single crystal of emerald. The laser may be operated over a broad temperature range from cryogenic temperatures to elevated temperatures. Emission is in a spectral range from red to infrared, and the laser is useful in the fields of defense, communications, isotope separation, photochemistry, etc.

16 MICRON CO2 LASER SYSTEM

Method and apparatus for inducing laser action in CO2 at a wavelength of 16 microns involving the transition between the 02.degree.0 and 0110 states. The population inversion between these two states is achieved by pumping to the 00.degree.1 level, suppressing the usual 10.6 micron transition to the 10.degree.0 level and encouraging the 9.6 micron transition, thereby populating the 02.degree.0 level, as the principal prerequisite for 16 micron laser action between the 02.degree.0 and 0110 levels.

16 MICRON CO2 LASER SYSTEM

STABLE MODE-LOCKED LASER FOR HIGH REPETITION RATE OPERATION

A laser system comprises a high-Q nonlinear optical resonator, a cavity comprising an amplifying element and a dispersive element, an optical delay line adapted to tune the length of the cavity, and a large pass-band filter adapted to tune the cavity's central oscillation wavelength, the nonlinear optical resonator being selected with a linewidth (LW R) comparable to the cavity free-spectral range (FSR C). There is provided a method for generating highly stable pulse streams, comprising providing a cavity comprising an amplifying element and a dispersive element; selecting a high-Q nonlinear optical resonator with a linewidth (LW R) comparable to the cavity free-spectral range (FSR C); tuning the length of the cavity; and tuning the cavity's central oscillation wavelength.

METHOD AND APPARATUS FOR LOCKING AND SCANNING THE OUTPUT FREQUENCY FROM A LASER CAVITY

A system and method that can be employed to lock and scan the output of a laser cavity (2) is described. The system and method involves the use of a signal generator for generating an error signal between an output of the laser cavity (28) and the transmission (28) of the laser through a tunable external reference cavity (3). A dual piezo-actuated mirror (6b) permits processing of the error signal (26) with separate signal processing circuits (29a, 29b) used to provide an electrical feedback signal to the two piezoelectric crystals (22, 23b). When incorporated within a laser cavity the described system and methodology can be used to lock and scan the output of the laser cavity while providing the laser output with a reduced linewidth.

LASER FOR GENERATING AN OPTICAL COMB

A laser for generating an optical comb is disclosed comprising an active laser medium enclosed in a resonator, means for coupling pump light from a pump source into the active medium, means for coupling out the generated laser comb, and at least one optical filter within the resonator for generating the comb. A filter for introducing a wavelength-dependent loss within the gain profile of the active medium is inserted in the resonator. As a result, the ring gain becomes unity over a wide range, and many modes of the comb start oscillating in the resonator.

Multiple wavelength laser construction - has lenses on rotating wheel sequentially altering incidence of beam from amplifier

LASER COMPRISING a TUNER IMPROVES

Bistable laser

TUNER FOR LASER HAS DYE

High repetition rate eximer laser system

Coherent/IM-DD dual operation optical transceiver

A dual-mode optical transceiver is disclosed. The dual-mode optical transceiver includes a receiver section configured to receive both coherently modulated and intensity modulated optical signals and to be optically switched between a first receiver mode for direct detection and a second receiver mode for coherent detection, and a transmitter section including a nested Mach-Zehnder Modulator or a polarization multiplexed quad Mach-Zehnder Modulator configured to be operated in a first transmission mode to output an intensity modulated optical signal and a second transmission mode to output a coherently modulated optical signal. In some implementations, the dual-mode optical receiver includes an optical switch configured to selectively direct a received optical signal down a direct detection optical circuit or a coherent detection optical circuit based on a control signal applied to the optical switch.

SINGLE LASER TRANSMITTER FOR Q-SWITCHED AND MODE-LOCKED VIBRATION OPERATION

A multifunctional laser (10) which, in a first operational mode, outputs a mode-locked beam for vibration sensing applications and, in a second operational mode, outputs a Q switched illumination beam for imaging applications. The inventive laser (10) includes a resonant cavity (110, 120, 190); a gain medium (100) disposed with the cavity; a first arrangement (150) in communication with the medium for causing a Qswitched signal to be transmitted from the cavity; a second arrangement (180) in communication with the medium for causing a mode-locked signal to be transmitted from the cavity; and a mechanism (130, 140) for switching between the first arrangement and the second arrangement.

MODE-LOCKED SEMICONDUCTOR LASER DIODE WITH DISPERSION-COMPENSATED EXTERNAL CAVITY

A semiconductor laser apparatus is provided. The semiconductor laser apparatus includes a mode-locked semiconductor laser device and an external resonator including a dispersion compensation system, wherein the semiconductor laser apparatus is configured to generate self modulation, to introduce a negative group velocity dispersion into the external resonator, and to provide spectral filtering after the external resonator.

PULSE SHAPER AND LASER WITH PULSE SHAPER

The present invention relates to a pulse shaper, comprising a first and a second dispersive element, wherein an optical pulse can be coupled to the pulse shaper (1) along a coupling direction such that said pulse exits from the pulse shaper after passing through the first and the second dispersive element along an exit direction, and the first and second dispersive element are adapted to be moveable relative to one another and disposed in such a way that the path length to be traversed by the optical pulse through the first and the second dispersive element after coupling to the pulse shaper can be adjusted without any change in a displacement (Δy) between the coupling direction and the exit direction. According to the invention, the first and the second dispersive element are disposed in such a way that the shape of the optical pulse experiences a change as the pulse travels through the pulse shaper (1), said change being caused primarily or exclusively by the group velocity dispersion ...

TUNABLE LIGHT MODULATION USING GRAPHENE

Described herein are optical devices based on two-dimensional materials and methods for making such devices. In particular, the articles described herein are useful in the control and modulation of light via graphene mono- or multilayers. methods for improved transfer of graphene from formation substrates to target substrates. The improved articles provide exceedingly high modulation depths in vis-NIR light transmission, with small insertion losses, thus revealing the potential of graphene for fast electro-optics within such a technologically important range of optical frequencies.

External-cavity optically-pumped semiconductor-laser with a resonator stop

An optically pumped semiconductor-laser (OPS-laser) resonator includes an arrangement for delivering optical pump radiation on an OPS-chip to cause fundamental radiation to circulate in the resonator. The resonator includes second and third-harmonic generating crystals and is arranged deliver third-harmonic radiation. The resonator also includes a stop positioned and configured to stabilize the laser output. The pump radiation arrangement delivers the pump radiation at an angle to the resonator axis and includes wedged GRIN lens arranged such that the pump radiation forms a circular spot on the OPS chip. The third harmonic generating crystal acts as a polarizer for the fundamental radiation and angularly separates fundamental and third harmonic beams.

ACOUSTICALLY COUPLED VIBRATION OF AN OPTICAL COMPONENT FOR REDUCING LASER COHERENCE EFFECTS INCLUDING SPECKLE

Systems and methods for reducing laser coherence effect within an optical system are disclosed. A system includes an acoustic device, a signal generator electrically coupled to the acoustic device, where the signal generator generates an electrical signal comprising a predefined frequency and a predefined amplitude for output by the acoustic device, and an optical system comprising a laser light source configured to produce a beam where one or more optical elements are disposed along the beam path that impinges or propagates through the one or more optical elements. The acoustic device is positioned at a distance from the one or more optical elements such that an acoustic signal emitted by the acoustic device causes one or more optical elements to vibrate such that laser coherence effects of the beam are reduced. 1. A system comprising:an acoustic device;a signal generator electrically coupled to the acoustic device, wherein the signal generator generates an electrical signal comprising a predefined frequency and a predefined amplitude for output by the acoustic device; andan optical system comprising a laser light source configured to produce a beam wherein one or more optical elements are disposed along a beam path that impinges or propagates through the one or more optical elements;wherein the acoustic device is positioned at a distance from the one or more optical elements such that an acoustic signal emitted by the acoustic device causes the one or more optical elements to vibrate such that laser coherence effects of the beam are reduced.2. The system of claim 1 , wherein the one or more optical elements is an optical element of the laser light source.3. The system of claim 1 , wherein the predefined frequency is a resonant frequency of at least one of the one or more optical elements of the optical system.4. The system of claim 1 , further comprising:a detector positioned within the optical system along the beam path of the beam produced by the laser light ...

OPTICAL GUIDED-MODE RESONANCE FILTER

A guided-mode resonance filer is provided which can be used as an optical filter with very narrow line width and as an efficient optical switch. Diffraction efficiencies and passband frequencies are calculated based on guided-mode resonance properties of periodic dielectric structures in a waveguide geometry. The guided-mode resonance filter preferably includes means for changing various parameters within the grating so as to change passband frequencies in response thereto. Also, the present invention envisions a narrowband tuneable laser having a diffraction grating of the present invention placed within a laser cavity to provide narrowband optical wave output from the narrowband tuneable laser In another preferred embodiment, the present diffraction grating can be supported by a semiconductor substrate, preferably adjacent to a semiconductor laser for fine-tuning the output of the semiconductor laser. In still another preferred embodiment, the present diffraction grating can be placed ...

Oscillator with mode control

An oscillator for isolating a transverse electromagnetic (TEM) zero-zero mode pulsed laser beam includes a laser pumping diode that is mounted on a base to induce a multi-mode laser beam from a lasing medium. As initially induced, the multi-mode laser beam is directed along a path and is characterized by a beating signal which has a frequency that is based on amplitude variations of laser pulses in the multi-mode laser beam. Electronics detect this beating signal and generates a responsive error signal. With closed loop control, the error signal is used to advance a straightedge toward the path of the multi-mode laser beam to remove transverse modes from the multi-mode laser beam with the straightedge. This advancement continues until the error signal is a null and the zero-zero mode pulsed laser beam is thereby isolated.

Scalable fast tunable Si-assisted hybrid laser with redundancy

The disclosed embodiments provide a tunable laser that includes a set of M reflective silicon optical amplifiers (RSOAs) and a set of N narrow-band reflectors. It also includes a silicon-photonic optical switch, having M amplifier ports, which are coupled through a set of M optical waveguides to the set of M RSOAs, and N reflector ports, which are coupled to the set of N narrow-band reflectors. The tunable laser also includes a switching mechanism that facilitates coupling at least one selected amplifier port from the M amplifier ports with a selected reflector port from the N reflector ports, thereby causing an RSOA coupled to the selected amplifier port to form a lasing cavity with a narrow-band reflector coupled to the selected reflector port. The tunable laser also includes a laser output, which is optically coupled to the lasing cavity.

OPTICAL SOURCE WITH PASSIVE PULSE SHAPING

The invention relates to sources of sub-picosecond optical pulses based on single-pass or double-pass optical amplifiers with an optical gain bandwidth in the 2-20 nm range. A passive pulse shaping filter is provided in front of the optical amplifier for pre-shaping seed optical pulses so as to passively pre-compensate for the gain narrowing effect in the optical amplifier. The passive pulse shaping filter may be based on a reflective thin film filter, which may be coupled to a mirror in a multi-pass configuration.

LASER SYSTEM

A laser system includes a first laser source with a laser resonator for generating a first pulsed laser beam. The resonator has a back mirror, an outcoupling mirror and an active lasing medium in between. The system includes a second laser source for generating a second pulsed laser beam and an optical block. The optical block includes a coupling polarizer and a first polarization rotator. The optical block is movable back and forth between an active position and a passive position. In its active position the optical block is located between the outcoupling mirror and the active lasing medium such that the coupling polarizer couples the second beam into the laser resonator of the first laser source while the first rotator is positioned between the outcoupling mirror and the coupling polarizer. In the active position of the optical block a second polarization rotator is between it and the back mirror.

WAVELENGTH TUNABLE RESONATOR WITH A PRISM

A wavelength tunable resonator comprises a first reflector(10) for reflecting an incident beam(5) of electromagnetic radiation towards a second reflector, said second reflector(50),said second reflector(50) for reflecting said beam(5) back towards said first reflector(10), said first and second reflector defining a resonator having an optical path with a length, a gain medium(20) for generating and emitting said beam(5) towards said first and second reflector(10 50), said laser source being arranged within said resonator, a prism (40), which is arranged within said optical path, serving to filter a wavelength of said beam (5) of electromagnetic radiation and being designed to redirect a portion of said incident beam comprising said filtered wavelength towards said second reflector( 50), wherein said second reflector is arranged to be movable with respect to other optical elements within said resonator for increasing or decreasing said length of said optical path of said resonator, and wherein ...

Single longitudinal mode fiber laser apparatus

The present invention provides a single frequency fiber laser apparatus. The fiber laser apparatus includes a Faraday rotator mirror. A piece of erbium doped fiber is inside the laser cavity. A wavelength selective coupler is connected to the erbium doped fiber. A pump source is coupled via the wavelength selective coupler. At least one sub-ring cavity component and/or an absorb component are inserted into the cavity for facilitating suppressing laser side modes to create a single longitudinal mode fiber laser. A partial reflectance fiber Bragg grating (FBG) is used as the front cavity end for this fiber laser.

Intra-cavity second harmonic generation (shg) laser device

A laser device for intra-cavity frequency conversion, in particular, for the second harmonic generation, the device comprising a laser cavity, formed by the first and the second laser cavity end reflectors wherein the said laser cavity end reflectors are highly reflective for the radiation about the laser fundamental frequency and as such provide for a predetermined level of circulating inside the cavity fundamental frequency power; an active medium provided within the said laser cavity; at least one non-linear crystal, in particular, for the second harmonic generation provided within the same laser cavity; tuning means adapted for tuning at least one of laser cavity end reflectors; wherein at least one of the laser cavity end reflectors comprises an interferometric layout providing spectrally selective reflection for the radiation about the laser fundamental frequency with the value of reflectivity nearly to 100% within a spectral range close to the free spectrum range of the laser cavity and with a sufficiently lower reflectivity outside the above spectral range such that the laser cavity restricts the spectrum of the laser radiation to a single longitudinal mode.

Intra-cavity optical parametric oscillator

An optical parametric oscillator comprising: an optical cavity; a semiconductor gain-medium located within the optical cavity, such that together they form a semiconductor laser, and a nonlinear material located within the cavity such that the nonlinear material continuously generates down-converted idler- and signal-waves in response to a pump-wave continuously generated by the semiconductor gain-medium, wherein the pump wave is resonant within the optical cavity and one or other but not both of the down-converted waves is resonant within the pump wave cavity or a further optical cavity. Brewster plates ensure singly resonant optical parametric oscillators and a birefringent filer is used for frequency setting. Coupled cavities allow for setting the photon lifetime in the cavity that relaxation oscillations are prevented.

Laser vibration sensor, system and method

A laser vibration sensor, system and method of vibration sensing employ a nanostructured resonance interactor. The sensor includes a resonator cavity of a laser and the nanostructured resonance interactor. The resonator cavity has a resonance deterministic of a characteristic of an output signal of the laser. The nanostructured resonance interactor modulates the resonance of the resonator cavity in response to a vibration. A change in the output signal characteristic induced by a resonance modulation is representative of the vibration. The system further includes an output signal detector. The method includes modulating a resonance characteristic of the resonator cavity using a nanostructure that responds to the vibration being sensed.

Actively Mode Locked Laser Swept Source for OCT Medical Imaging

An optical coherence analysis system uses a laser swept source that is constrained to operate in a mode locked condition. This is accomplished by synchronously changing the laser cavity's gain and/or phase based on the round trip travel time of light in the cavity. This improves high speed tuning by taking advantage of frequency shifting mechanisms within the cavity and avoids chaotic laser behavior.

Pulse fiber laser device

A pulse fiber laser device 1 has a Fabry-Perot type optical resonator, and is provided with an excitation light source 11 , an optical coupling unit 12 , an amplifying optical fiber 13 , a saturable absorber 14 , a gradient index lens 15 , an optical output unit 16 , a dispersion adjusting unit 17 , a mirror 21 and a mirror 22 . The saturable absorber 14 and the mirror 21 , integrated into one body, constitute a saturable absorber mirror 23 . The gradient index lens 15 converges the light output from an end face of an optical fiber 32 and outputs the light to the saturable absorber mirror 23 , and inputs the light reflected from the saturable absorber mirror 23 into the end face of the optical fiber 32 . Thus, there is provided a pulse fiber laser device that enables easy adjustment of the intensity of light incident on a saturable absorber and facilitates miniaturization.

PRODUCES VARIOUS TYPES OF PULSES BY CONTROLLING THE DISTANCE BETWEEN THE SATURABLE ABSORBER CONNECTORS

Provided is a device of generating various types of pulses by controlling a distance between saturable absorber connectors, and more particularly, a device of generating various types of pulses by controlling a distance between saturable absorber connectors, capable of actively controlling a distance between saturable absorbers to completely overcome a disadvantage that an opened space is present in a cavity or a disadvantage that a fiber component should be changed and implementing a simple design of the entire fiber laser cavity since only a saturable absorber part, which is a portion of a fiber laser cavity, should be designed, as a carbon nanotube saturable absorber part in a passively mode-locked fiber laser generating apparatus using the saturable absorber. 1. A device of generating various types of pulses by controlling a distance between saturable absorber connectors , the device comprising:{'b': 500', '100', '110', '120', '200', '100', '300', '200', '200, 'a saturable absorber moving unit including a saturable absorber mounting part having one portion to which a saturable absorber is coupled and the other portion to which a fiber is coupled, a fiber fixing part having one portion to which the saturable absorber mounting part is coupled, and a micro driving part coupled to the other portion of the fiber fixing part to horizontally move the fiber fixing part ;'}{'b': 600', '100', '110', '120', '200', '100', '500, 'a saturable absorber fixing unit including a saturable absorber mounting part having one portion to which a saturable absorber is coupled and the other portion to which a fiber is coupled and a fiber fixing part having one portion to which the saturable absorber mounting part is coupled, and fixed to be spaced apart from the saturable absorber moving unit by a predetermined distance; and'}{'b': 700', '500', '600, 'a fiber connecting unit provided between the saturable absorber moving unit and the saturable absorber fixing unit to be fixed.'} ...

Laser apparatus

A laser apparatus includes a master oscillator capable of outputting a laser beam having a spectrum that includes at least three wavelength peaks, a multi-wavelength oscillation control mechanism capable of controlling energy of each of the wavelength peaks, a spectrum detecting unit that detects the spectrum of the above-mentioned laser beam, and a controller that controls the multi-wavelength oscillation control mechanism based on a detection result detected by the spectrum detecting unit.

Master oscillator system and laser apparatus

A master oscillator system may include a grating configured to function as one resonator mirror in an optical resonator, a spectral bandwidth tuning unit configured to tune the spectral bandwidth of a laser beam transmitted within the optical resonator, a storage unit configured to store a control value of the spectral bandwidth tuning unit corresponding to a desired spectral bandwidth and a controller configured to control the spectral bandwidth tuning unit based on the control value stored in the storage unit.

Translucent polycrystalline material and manufacturing method thereof

Provided is a method for manufacturing a translucent polycrystalline material with optical properties continuously varying in the material. A slurry including single crystal grains that are acted upon by a force when placed in a magnetic field is immobilized in a gradient magnetic field with a spatially varying magnetic flux density and then sintered. For example, where a slurry including single crystal grains of YAG doped with Er and single crystal grains of YAG undoped with a rare earth material is immobilized in the gradient magnetic field, the region with a strong magnetic field becomes a laser oscillation region that is rich in Er-doped YAG, whereas the region with a weak magnetic field becomes a translucent region rich in YAG undoped with a rare earth material. A polycrystalline material having a core with laser oscillations and a guide surrounding the core are obtained at once.

External Cavity Wideband Tunable Laser with Dual Laser Gain Media Coupled by a Thin Film Filter Including

The invention relates to an external cavity wideband tunable laser with dual laser gain media coupled by a thin film filter. The laser comprises: a first laser gain medium, a first laser cavity end mirror arranged on the first laser gain medium, a first intracavity collimating lens, an active optical phase modulator, a tunable acousto-optic filter, an intracavity reflection mirror, an etalon and a total reflection mirror, which are all arranged sequentially inside the laser cavity. The laser further comprises a second laser gain medium, a second laser cavity end mirror arranged on the second laser gain medium, a second intracavity collimating lens, a thin film optical filter for coupling the output light beams emitted from the first laser gain medium and the second laser gain medium, a radio frequency signal source, pumping sources for the two laser gain media, an active optical phase modulator drive source and a laser drive control circuit. The invention expands the output spectrum range of a single tunable laser and is capable of covering C and L spectrum bands. The laser has reliable performance with stable output and compact size, low cost for volume production and easy installation. 1. An external cavity wideband tunable laser with dual laser gain media coupled by a thin film filter including: a first laser gain medium , a first laser cavity end mirror arranged on the first laser gain medium , a first intracavity collimating lens , an active optical phase modulator , a tunable acousto-optic filter , an intracavity reflection mirror , which are all arranged sequentially , an etalon and a total reflection mirror , which are arranged on the opposite side of the tunable acousto-optic filter from the intracavity reflection mirror , the laser further comprises:a second laser gain medium, a second laser cavity end mirror arranged on the second laser gain medium, a second intracavity collimating lens, the optical axes of second laser gain medium and the second ...

Precision Optical Frequency Tunable Laser

The invention relates to a precision optical frequency tunable laser. The laser includes: a laser gain medium, an intracavity collimating lens, an active optical phase modulator, a tunable acousto-optic filter and an intracavity total reflection mirror all arranged sequentially in a laser cavity, and the tunable laser further includes an active polarization rotator, a polarization beam splitter, two etalons, a temperature control system attached to the etalons, two total reflection mirrors, a radio frequency signal source, a laser pumping source, an active optical phase modulator drive source, an active polarization rotator drive source and a laser drive control circuit. Through the temperature control system attached to the etalons, stable laser output and the precision optical frequency tuning less than 1 GHz within a wide spectrum range can be realized, thereby greatly reducing the bandwidth requirements in achieving narrowband filtering for the tunable acousto-optic filter. The invention is compact with high performance, low cost for volume production and installation, and achieves stable tunable laser output within a wide spectrum range. 1. A precision optical frequency tunable laser comprising a laser gain medium , a laser cavity end mirror arranged on the laser gain medium , an intracavity collimating lens , an active optical phase modulator , a tunable acousto-optic filter and an intracavity total reflection mirror all arranged sequentially inside the laser cavity and in such a way that the light beam emitted from the laser gain medium can be diffracted twice by the tunable acousto-optic filter and the frequency shift introduced by the diffractions can be compensated , the laser further comprises:an active polarization rotator for controlling the polarization direction of linearly polarized incident light, the active polarization rotator is arranged on the opposite side of the tunable acousto-optic filter from the intracavity total reflection mirror to ...

Methods, Systems, and Devices for Timing Control in Electromagnetic Radiation Sources

In one embodiment, the invention relates to systems, methods and devices for improving the operation of an electromagnetic radiation source or component thereof. In one embodiment, the source is a laser source. A Fourier domain mode locked laser can be used in various embodiments. The sources described herein can be used in an optical coherence tomography (OCT) system such as a frequency domain OCT system. In one embodiment, laser coherence length is increased by compensating for dispersion. A frequency shifter can also be used in one embodiment to compensate for a tunable filter induced Doppler shift.

Laser Swept Source with Controlled Mode Locking for OCT Medical Imaging

An optical coherence analysis system uses a laser swept source that is constrained to operate in a mode locked condition. This is accomplished by synchronously changing the laser cavity's gain and/or phase based on the round trip travel time of light in the cavity. Many high-speed wavelength swept laser sources emit pulses synchronized with the round trip time of the cavity as part of a nonlinear optical frequency red shifting process. Stable pulsation is associated with smooth tuning and low relative intensity noise. Addition of mode-locking methods to this class of lasers can control and stabilize these lasers to a low clock jitter and RIN state, and in specific cases allow long-to-short wavelength tuning in addition to the usual short-to-long (red shifting). The laser may comprise a SOA ( 410 ), a tunable Fabry-Perot-Filter ( 412 ) as one reflector and an Output coupler ( 405 ) in an optical fiber ( 406 ) to adjust the cavity length.

Laser apparatus and photoacoustic apparatus

A laser apparatus that allows selection of a wavelength of output light from a plurality of options. The laser apparatus includes: a resonator made up from an output mirror and reflection means having a plurality of reflective surfaces fixed in position; a laser medium disposed on an optical axis inside the resonator; branch means branching an optical path of a light beam formed on the optical axis when light oscillates in the laser medium into a plurality of optical paths having an end at one reflective surface of the reflection means, the branch means forming a first optical path coinciding with the optical axis when located out of the optical axis, and forming a branch path by moving the light of the optical axis parallel when located on the optical axis.

Broad band continuous tunable laser

The invention relates to a broad band continuous tunable laser. The laser includes a first laser cavity mirror, a laser gain medium, an intracavity collimating lens, an active optical phase modulator, a tunable acousto-optic filter, and the tunable laser further includes an intracavity reflection mirror to reflect the first order diffracted beam of the first diffraction back to the tunable acousto-optic filter to compensate the wavelength shift, a tunable Fabry-Perot filter arranged in the optical path of the second diffraction beam, a second laser cavity mirror and a laser drive and control circuit system. A stable laser output and the precision optical frequency tuning for less than 1 GHz frequency accuracy within a wide spectrum range can be realized. The invention is compact with stable performance, low cost for volume production and easy installation without moving parts. 1. A broad band continuous tunable laser comprising a first laser cavity mirror , a laser gain medium , an intracavity collimating lens , an active optical phase modulator , a tunable acousto-optic filter , an intracavity reflection mirror , a tunable Fabry-Perot filter , a second laser cavity mirror and a laser drive and control circuit system; the tunable Fabry-Perot filter includes a first reflection mirror , a liquid crystal module , and a second reflection mirror; the first reflection mirror , and the second reflection mirror forms a Fabry-Perot cavity , the liquid crystal module is arranged inside the Fabry-Perot cavity; the intracavity collimating lens collimates the light beam outputted from the laser gain medium and inputs the collimated beam into the tunable acousto-optical filter at Bragg angle to generate the first diffraction after passing through the active optical phase modulator; the intracavity mirror is arranged on the opposite side of the acousto-optic filter from the laser gain medium to reflect the first order diffracted beam of the first diffraction by the tunable acousto ...

Methods and Apparatus for Swept-Source Optical Coherence Tomography

In one embodiment of the invention, a semiconductor optical amplifier (SOA) in a laser ring is chosen to provide low polarization-dependent gain (PDG) and a booster semiconductor optical amplifier, outside of the ring, is chosen to provide high polarization-dependent gain. The use of a semiconductor optical amplifier with low polarization-dependent gain nearly eliminates variations in the polarization state of the light at the output of the laser, but does not eliminate the intra-sweep variations in the polarization state at the output of the laser, which can degrade the performance of the SS-OCT system. 120-. (canceled)21. An optical imaging system comprising: a first gain element,', 'a tunable filter in optical communication with the first gain element, the tunable filter comprising a drive waveform input, and', 'an output of the tunable laser in optical communication with the tunable filter;, 'a tunable laser comprising'}a first optical coupler in optical communication with the output of the tunable laser; and a source input in optical communication with the first optical coupler,', 'a sample arm in optical communication with the source input, wherein the sample arm is configured to transmit light to an optical probe and receive scattered light acquired by the optical probe, and', 'a first interferometer output., 'a first interferometer comprising'}22. The system of further comprisinga polarization controller in optical communication with the tunable laser output anda second gain element in optical communication with an output of the polarization controller, wherein the second gain element is a booster optical amplifier.23. The system of further comprising a display system comprising a computer in electrical communication with a display claim 21 , wherein the display system is configured to display images using the display claim 21 , the computer claim 21 , and data received thereby claim 21 , wherein the data is generated in response to interference signals ...

WAVELENGTH LOCKER USING MULTIPLE FEEDBACK CURVES TO WAVELENGTH LOCK A BEAM

A device may include a first photodetector to generate a first current based on an optical power of an optical beam. The device may include a beam splitter to split a portion of the optical beam into a first beam and a second beam. The device may include a wavelength filter to filter the first beam and the second beam. The wavelength filter may filter the second beam differently than the first beam based on a difference between an optical path length of the first beam and an optical path length of the second beam through the wavelength filter. The device may include second and third photodetectors to respectively receive, after the wavelength filter, the first beam and the second beam and to generate respective second currents. 126-. (canceled)27. A device , comprising:a laser emitter to generate a laser beam to be wavelength locked to a target frequency based on an emission frequency to be measured by the device; 'the laser beam to be wavelength locked based on the first current;', 'a first photodetector to generate a first current based on a first optical power of the laser beam,'}a beam splitter to split a portion of the laser beam into a first beam and a second beam; the patterned etalon to have different optical path lengths for the first beam and the second beam, and', 'the patterned etalon to filter the first beam and the second beam to a second optical power and a third optical power, respectively, based on the different optical path lengths; and, 'a patterned etalon to filter the first beam and the second beam,'} 'a selected current, of the respective second currents, to be used to wavelength lock the laser beam.', 'second and third photodetectors to generate respective second currents,'}28. The device of claim 27 , wherethe beam splitter is further to split the portion of the laser beam into a third beam and a fourth beam, andthe third beam is received by the first photodetector without being filtered by the patterned etalon.29. The device of claim 27 , ...

LASER LIGHT-SOURCE APPARATUS AND LASER PULSE LIGHT GENERATING METHOD

A laser light-source apparatus includes: fiber amplifiers and a solid state amplifier configured to amplify pulse light output from a seed light source based on gain switching; nonlinear optical elements configured to perform wavelength conversion on the pulse light output from the solid state amplifier; an optical switching element configured to permit or stop propagation of pulse light from the fiber amplifier to the solid state amplifier; and a control unit configured to control the optical switching element in such a manner that the propagation of the light is stopped in an output period of the pulse light from the seed light source, and permitted in a period other than the output period of the pulse light from the seed light source. 19.-. (canceled)10. A laser light-source apparatus comprising:a seed light source configured to output pulse light based on gain switching;a fiber amplifier configured to amplify the pulse light output from the seed light source;a solid state amplifier configured to amplify the pulse light output from the fiber amplifier;a nonlinear optical element configured to perform wavelength conversion on the pulse light output from the solid state amplifier and output the resultant pulse light;an optical switching element that is disposed between the fiber amplifier and the solid state amplifier, and is configured to permit or stop propagation of light from the fiber amplifier to the solid state amplifier; anda control unit configured to control the optical switching element in such a manner that the propagation of the light is stopped in an output period of the pulse light from the seed light source, and permitted in a period other than the output period of the pulse light from the seed light source to achieve an output stopped state in which the output of the pulse light from the nonlinear optical element is stopped.11. The laser light-source apparatus according to claim 10 , wherein the control unit is configured to periodically or ...

Tunable Laser

Examples of the present disclosure include a tunable laser comprising a waveguide including gain section. The waveguide overlies and is optically coupled to another waveguide. The another waveguide has a reflector at one end. A laser cavity is formed in the waveguides. 1. A tunable laser comprising:a first waveguide comprising a first III-V semiconductor material and including a first gain section;a second waveguide comprising a second III-V semiconductor material and including a second gain section;an optical coupler to couple light between the first waveguide and the second waveguide;wherein the first waveguide overlies and is optically coupled to a third waveguide which comprises a third III-V semiconductor material, the third waveguide having a width which is greater than a largest width of the first gain section of the first waveguide;wherein the second waveguide overlies and is optically coupled to a fourth waveguide which comprises a fourth III-V semiconductor material, the fourth waveguide having a width which is greater than a largest width of the second gain section of the second waveguide; andwherein a first laser cavity is formed between the optical coupler and a reflector of the third waveguide and a second laser cavity is formed between the optical coupler and a reflector of the fourth waveguide.2. The tunable laser of wherein the first waveguide includes a first taper transition tip to couple light from the first waveguide to the third waveguide and the second waveguide includes a second taper transition tip to couple light from the second waveguide to the fourth waveguide.3. The tunable laser of wherein the effective refractive index of the first gain section of the first waveguide is higher than an effective refractive index of the third waveguide.4. The tunable laser of wherein the third waveguide is a diluted waveguide including a plurality of alternating layers claim 3 , a first one of said alternating layers comprising a third III-V ...

WAVELENGTH-TUNABLE TYPE ETALON COMPRISING LCD-LAYER AND PREPARATION METHOD THEREOF

The present invention relates to a wavelength-tunable type etalon comprising a liquid crystal layer, which comprises: a first substrate; a second substrate; a reflective coating film; a transparent electrode; an alignment layer, which is independently formed while covering the opposing surface of the transparent electrode; a liquid crystal layer, which is disposed in a space between each of the alignment layer s; and a sealing member, which is provided for sealing of the liquid crystal layer; and a method for manufacturing the same. 1. A wavelength-tunable type etalon comprising a liquid crystal layer , comprising:a first substrate;a second substrate;a pair of reflective coating films, which is provided at inner surface side of the first and second substrate, respectively;a pair of transparent electrodes, which is provided at intermediate of the first and second substrate;a pair of alignment layers, which is provided at intermediate of the first and second substrate;a liquid crystal layer, which is disposed in a cavity between each of the alignment layers; anda sealing member, which is provided for sealing of the liquid crystal layer.2. The wavelength-tunable type etalon of claim 1 , wherein the first and second substrates comprise at least one selected from glass claim 1 , quartz claim 1 , and silicon wafer so as to be substantially transparent in the band of 1300 nm to 1700 nm.3. The wavelength-tunable type etalon of claim 2 , wherein the alignment layer comprises an inorganic insulating film.4. The wavelength-tunable type etalon of claim 3 , wherein the inorganic insulating film comprises SiOor SiN.5. The wavelength-tunable type etalon of claim 3 , wherein the inorganic insulating film has a thickness in the range of 30 nm to 200 nm claim 3 , respectively.6. The wavelength-tunable type etalon of claim 3 , wherein the sealing member is provided along the periphery of the liquid crystal layer between the first and second substrates claim 3 , and is provided in ...

Coherent Combining Pulse Bursts In Time Domain

A beam combining and pulse stacking technique is provided that enhances laser pulse energy by coherent stacking pulse bursts (i.e. non-periodic pulsed signals) in time domain. This energy enhancement is achieved by using various configurations of Fabry-Perot, Gires-Tournois and other types of resonant cavities, so that a multiple-pulse burst incident at either a single input or multiple inputs of the system produces an output with a solitary pulse, which contains the summed energy of the incident multiple pulses from all beams. This disclosure provides a substantial improvement over conventional coherent-combining methods in that it achieves very high pulse energies using a relatively small number of combined laser systems, thus providing with orders of magnitude reduction in system size, complexity, and cost compared to current combining approaches. 118.-. (canceled)19. A system for coherently combining pulses of a pulsed optical signal in the time domain , comprising:a first combining stage configured to receive an optical input signal and comprised of one or more resonant cavities arranged in a sequential manner with each other, wherein the optical input signal has one or more clusters of pulses in a pulse train, such that amplitude and phase of pulses in the one or more clusters varies amongst pulses, and wherein each resonant cavity in the first combining stage has an entirely reflective cavity and operates to coherently combine pulses in the one or more clusters in the time domain to form an output signal; anda second combining stage configured to receive the output signal from the first combining stage and comprised of one or more resonant cavities arranged in a sequential manner with each other, wherein each resonant cavity in the second combining stage has an entirely reflective cavity and operates to coherently combine pulses in the output signal in the time domain.20. The system of wherein each of the one or more resonant cavities in the first combining ...

DARK CAVITY LASER

The present disclosure provides a dark cavity laser, including: a frequency stabilized laser output device configured to generate a laser light, and perform a frequency stabilized processing on the generated laser light to output it to the dark cavity laser device as a pump light of a gain medium of a dark cavity; and a dark cavity laser device including a main cavity, and a cavity of the main cavity is provided inside with a gas chamber of a gain medium of a dark cavity laser light, where the gain medium of the dark cavity laser light is alkali metal atoms; the dark cavity laser device is configured to receive the pump light, and form a polyatomic coherent stimulated radiation between transition levels of the alkali metal atoms in the gas chamber by a weak feedback of the main cavity to generate the dark cavity laser light. 1. A dark cavity laser , comprising: a frequency stabilized laser output device and a dark cavity laser device;wherein the frequency stabilized laser output device is configured to generate a laser light, and perform a frequency stabilized processing on the generated laser light to output it to the dark cavity laser device as a pump light of a gain medium of a dark cavity; andthe dark cavity laser device includes a main cavity, and a cavity of the main cavity is provided inside with a gas chamber of a gain medium of a dark cavity laser light, wherein the gain medium of the dark cavity laser light is alkali metal atoms; the dark cavity laser device is configured to receive the pump light, and form a polyatomic coherent stimulated radiation between transition levels of the alkali metal atoms in the gas chamber by a weak feedback of the main cavity to output the dark cavity laser light.2. The dark cavity laser according to claim 1 , wherein the cavity of the main cavity further comprises inside: a piezoelectric ceramic with a large displacement configured to adjust a cavity length of the main cavity to change a cavity mode frequency of the main ...

METHOD FOR CONTROLLING WAVELENGTH-TUNABLE LASER

The method for controlling a wavelength-tunable laser comprises a first step of acquiring a driving condition of the wavelength-tunable laser for laser oscillation at a first wavelength, and a second step of calculating according to the driving condition of the first wavelength and a wavelength difference between the first wavelength and a second wavelength different from the first wavelength a control value or target value of a wavelength characteristic of the second wavelength in the wavelength detection unit, so as to calculate a driving condition for driving the wavelength-tunable laser, the second step including a step of selecting according to the wavelength difference one of etalon slopes having respective gradients identical and opposite to a gradient of an etalon slope used for controlling the first wavelength. 1. A method for controlling a wavelength-tunable laser comprising a wavelength detection unit having an etalon , the method comprising:a first step of acquiring a driving condition of the wavelength-tunable laser for laser oscillation at a first wavelength;a second step of calculating according to the driving condition of the first wavelength and a wavelength difference between the first wavelength and a second wavelength different from the first wavelength a control value or target value of a wavelength characteristic of the second wavelength in the wavelength detection unit, so as to calculate a driving condition for driving the wavelength-tunable laser; anda third step of feedback-controlling an oscillation wavelength according to a difference between a result of detection of a wavelength by the wavelength detection unit and the target value;wherein the second step includes a step of selecting according to the wavelength difference one of etalon slopes having respective gradients identical and opposite to a gradient of an etalon slope used for controlling the first wavelength.2. The method for controlling a wavelength-tunable laser according to ...

EXPOSURE APPARATUS AND EXPOSURE METHOD

An exposure apparatus is an exposure apparatus for forming a pattern by exposure by irradiating a set master with laser light, comprising: an optical pickup which is capable of adjusting the focus of laser light and a control unit which adjusts the focus of laser light emitted from the optical pickup using integrated surface profile data indicating the relative positional relationship between the surface of the master and the optical pickup according to at least one of the surface roughness of the master the inclination of the master and the decentering of the master 1. An exposure apparatus for forming a pattern by exposure by irradiating a set master with laser light , comprising:a light source unit emitting the laser light and capable of adjusting a focus of the laser light; anda control unit adjusting a focus of laser light emitted from the light source unit using integrated surface profile data indicating a relative positional relationship between a surface of the master and the light source unit depending on at least one of surface roughness of the master, inclination of the master, and decentering of the master.2. The exposure apparatus according to claim 1 , whereinthe control unit comprises:an error detection unit performing output corresponding to a focus error of the laser light;an adder adding a target value corresponding to an output from the error detection unit with the laser light focusing on the surface of the master and an offset value based on a correction signal generated based on the integrated surface profile data; anda control computing unit adjusting a focus of the laser light based on a difference between a sum obtained by the adder and the output from the error detection unit.3. The exposure apparatus according to claim 2 , whereinthe correction signal is one of a table and a function corresponding to the position of the surface of the master.4. The exposure apparatus according to claim 1 , whereinthe control unit comprises:an error ...

DYNAMICALLY ADDRESSABLE HIGH VOLTAGE OPTICAL TRANSFORMER WITH INTEGRATED OPTICALLY TRIGGERED SWITCHES

An optical transformer includes a plurality of light emitters, a plurality of photovoltaic cells positioned to receive light from at least a first subset of the plurality of light emitters, the plurality of photovoltaic cells including at least a first photovoltaic cell and a second photovoltaic cell, and one or more optically triggered switches positioned to receive light from at least a second subset of the plurality of light emitters, the one or more optically triggered switches including at least a first optically triggered switch electrically coupled to the first photovoltaic cell and the second photovoltaic cell. A method of operating the optical transformer is also described. 1. An optical transformer , comprising:a plurality of light emitters;a plurality of photovoltaic cells positioned to receive light from at least a first subset of the plurality of light emitters, the plurality of photovoltaic cells including at least a first photovoltaic cell and a second photovoltaic cell; andone or more optically triggered switches positioned to receive light from at least a second subset of the plurality of light emitters, the one or more optically triggered switches including at least a first optically triggered switch electrically coupled to the first photovoltaic cell and the second photovoltaic cell.2. The optical transformer of claim 1 , wherein the first optically triggered switch electrically couples the first photovoltaic cell and the second photovoltaic cell while the first optically triggered switch is in a first illumination state and the first optically triggered switch forgoes electrically coupling the first photovoltaic cell and the second photovoltaic cell while the first optically triggered switch is in a second illumination state that is distinct from the first illumination state.3. The optical transformer of claim 2 , wherein the first optically triggered switch electrically couples the first photovoltaic cell and the second photovoltaic cell in ...

DEVICE FOR INTERFEROMETRIC DISTANCE MEASUREMENT

A device for interferometric distance measurement includes a multiple wavelength light source, which supplies a light beam having at least three different wavelengths and is configured as a fiber laser, which includes at least three different Bragg gratings, whose grating constants are matched to the wavelengths generated. In addition, an interferometer unit is provided, which splits up the light beam into a measuring light beam and a reference light beam. The measuring light beam propagates in a measuring arm, in the direction of a measuring reflector, and there, it is reflected back; the reference light beam propagates in a reference arm, in the direction of a stationary reference reflector, and there, it is reflected back. The measuring and reference light beams reflected back by the measuring and reference reflectors are superimposed in an interfering manner to form an interference light beam. The interference light beam is split up via a detection unit such that, in each instance, a plurality of phase-shifted, partial interference signals result per wavelength. With the aid of a signal processing unit, an absolute position information item regarding the measuring reflector is determined from the partial interference signals of different wavelengths. 1. A device for interferometric distance measurement , comprising:a multiple wavelength light source adapted to emit a light beam having at least three different wavelengths and arranged as a fiber laser including at least three different Bragg gratings having grating constants matched to the wavelengths;an interferometer unit adapted to split up the light beam into a measuring light beam that propagates in a measuring arm in a direction of a measuring reflector and that is reflected back by the measuring reflector and into a reference light beam that propagates in a reference arm in a direction of a stationary reference reflector and that is reflected back by the reference reflector, the measuring and reference ...

Laser Closed Power Loop with an Acousto-Optic Modulator for Power Modulation

A laser-beam power-modulation system includes an acousto-optic modulator (AOM) to receive a laser beam and separate the laser beam into a primary beam and a plurality of diffracted beams based on an input signal. The power of the primary beam depends on the input signal. The system also includes a slit to transmit the primary beam and dump the plurality of diffracted beams, a controller to generate a control signal based at least in part on feedback indicative of the power of the primary beam or the power of a beam generated using the primary beam, and a driver to generate the input signal based at least in part on the control signal. 1. A laser-beam power-modulation system , comprising:an acousto-optic modulator to receive a laser beam and separate the laser beam into a primary beam and a plurality of diffracted beams based on an input signal, wherein the power of the primary beam depends on the input signal;a slit to transmit the primary beam and dump the plurality of diffracted beams;a controller to generate a control signal based at least in part on feedback indicative of the power of the primary beam or the power of a beam generated using the primary beam; anda driver to generate the input signal, based at least in part on the control signal.2. The system of claim 1 , further comprising:one or more mirrors to direct the primary beam and the plurality of diffracted beams toward the slit; anda sensor to receive light from the primary beam leaked by a respective mirror of the one or more mirrors and to provide the feedback indicative of the power of the primary beam based on the received light;wherein the controller is to generate the control signal based at least in part on the feedback indicative of the power of the primary beam.3. The system of claim 2 , wherein:the one or more mirrors comprise a first mirror and a second mirror;the first mirror is situated between the acousto-optic modulator and the second mirror in the optical paths of the primary beam and ...

Synchronized tunable mode-locked lasers

A synchronized laser system for illuminating a sample with first and second laser light pulses, said system comprising: a trigger, said trigger being operative to issue first and second trigger signals, said first and second trigger signals being emitted at an adjustable frequency with a predetermined delay therebetween; a first tunable mode-locked laser operative for emitting said first laser light pulses in response to receiving a train of said first trigger signals, a first wavelength of said first laser light pulses being dependent on said adjustable frequency in accordance with a first wavelength-frequency relationship; a second tunable mode-locked laser operative for emitting said second laser light pulses in response to receiving a train of said second trigger signals, a second wavelength of said second laser light pulses being dependent on said adjustable frequency in accordance with a second wavelength-frequency relationship; wherein said predetermined delay is such that said first and second laser light pulses are emitted so as to arrive substantially simultaneously in said sample; and said first and second wavelength-frequency relationships are selected to result in a predetermined relationship between said first and second wavelengths at each frequency.

Optical Coherence Tomography Laser with Integrated Clock

A frequency swept laser source for TEFD-OCT imaging includes an integrated clock subsystem on the optical bench with the laser source. The clock subsystem generates frequency clock signals as the optical signal is tuned over the scan band. Preferably the laser source further includes a cavity extender in its optical cavity between a tunable filter and gain medium to increase an optical distance between the tunable filter and the gain medium in order to control the location of laser intensity pattern noise. The laser also includes a fiber stub that allows for control over the cavity length while also controlling birefringence in the cavity. 1. A sampling clock system for an optical coherence analysis system including a swept source generating a tunable optical signal , an interferometer that receives the tunable optical signal from the swept source via an optical fiber and conveys the optical signal on a reference arm and a sample arm and combines the optical signal returning from the reference arm and the sample arm to generate a combined signal , a detector system that detects the combined signal , and a sampling system that samples an output of the detector system and receives an electronic clock , the sampling clock system comprising:an optical detector for detecting an optical clock signal generated by optically filtering the tunable optical signal from the swept source to generate the electronic clock; andan electronic time delay circuit for delaying the electronic clock by an amount corresponding to the propagation time of the light from the swept source in the optical coherence analysis system that includes the optical fiber, the interferometer arms and path to the detector system to improve delay matching between the electronic clock and the combined signal.2. A system as claimed in claim 1 , wherein the electronic time delay circuit imparts a programmable delay to the electronic clock.3. A system as claimed in claim 1 , further comprising a high pass filter ...

LASER LIGHT-SOURCE APPARATUS AND LASER PULSE LIGHT GENERATING METHOD

A laser light-source apparatus includes; a seed light source; a fiber amplifier configured to amplify pulse light output from the seed light source based on gain switching; a solid state amplifier configured to further amplify the resultant pulse light; a nonlinear optical element configured to perform wavelength conversion on the pulse light output from the solid state amplifier; an optical switching element that is disposed between the fiber amplifier and the solid state amplifier and is configured to remove ASE noise; and a control unit. The control unit is configured to control the optical switching element in such a manner that propagation of light is permitted in an output period of the pulse light from the seed light source, and is stopped in a period other than the output period. 1. A laser light-source apparatus comprising:a seed light source configured to output pulse light based on gain switching;a fiber amplifier configured to amplify the pulse light output from the seed light source;a solid state amplifier configured to amplify the pulse light output from the fiber amplifier;a nonlinear optical element configured to perform wavelength conversion on the pulse light output from the solid state amplifier and output the resultant pulse light:an optical switching element that is disposed between the fiber amplifier and the solid state amplifier, and is configured to permit or stop propagation of light from the fiber amplifier to the solid state amplifier; anda control unit configured to execute:gain switching control processing in which the seed light source is driven at a predetermined cycle;excitation control processing in which an excitation light source of the fiber amplifier and/or the solid state amplifier is periodically or intermittently controlled in such a manner that the fiber amplifier and/or the solid state amplifier enters a population inversion state before receiving the pulse light output from the seed light source; andoptical switch control ...

PULSED LASER SOURCES

Modelocked fiber laser resonators may be coupled with optical amplifiers. An isolator optionally may separate the resonator from the amplifier. A reflective optical element on one end of the resonator having a relatively low reflectivity may be employed to couple light from the resonator to the amplifier. Enhanced pulse-width control may be provided with concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers. Apodized fiber Bragg gratings and integrated fiber polarizers may also be included in the laser cavity to assist in linearly polarizing the output of the cavity. Very short pulses with a large optical bandwidth may be obtained by matching the dispersion value of the grating to the inverse of the dispersion of the intra-cavity fiber. Frequency comb sources may be constructed from such modelocked fiber oscillators. Low dispersion and an in-line interferometer that provides feedback may assist in controlling the frequency components output from the comb source. 1. A frequency comb source comprising:a mode-locked fiber oscillator comprising optical fiber disposed in an optical cavity;a non-linear optical element disposed to receive pulsed output from said mode-locked fiber oscillator and to generate a supercontinuum comprising a first train of optical pulses having a first set of frequency components;an interferometer disposed to receive said first train of optical pulses, said interferometer comprising a frequency converter comprising a nonlinear waveguide and configured to generate a second train of optical pulses having a second set of frequency components that are shifted in frequency with respect to the first set of frequency components, said second train of optical pulses temporally overlapping said first set of optical pulses, said interferometer configured to interfere at least a portion of said first train and said second train of optical pulses to generate an optical interference signal comprising beat frequencies; ...

Nanosecond ti:sapphire laser

A laser according to an exemplary embodiment of the present invention includes a pump laser outputting laser light, and a laser resonator including a laser crystal and an acoustic optical modulator and resonating the laser light output from the pump laser, wherein the pump laser is a Nd:YAG, and the laser crystal is Ti:Sapphire.

Q-switched fiber laser

A fiber laser, null coupler acoustic Q-switch, fiber amplifier and feedback system is described for generation of high power laser pulses.

Laser device and laser processing machine

A laser device includes: a plurality of laser diodes that emit laser beams having different wavelengths; a partial reflection mirror that resonates the plurality of laser beams emitted by the plurality of laser diodes; and a wavelength dispersion element that causes the plurality of laser beams incident from the plurality of laser diodes in different orientations of optical axes of the laser beams to travel to the mirror with the optical axes aligned. Each of the plurality of laser diodes is integrally formed with an adjustment component that is rotatable around an emission end of the laser diode.

APPARATUS FOR TUNING DISCHARGE PERFORMANCE IN A LASER CHAMBER

Disclosed is a laser discharge chamber in which useful lifetime is extended by local electrical tuning using one or a combination of design of the chamber internal geometry, placement and distribution of components within the chamber such as electrodes, current returns, and capacitors, and selective electrical isolation of portions of the components 1. Apparatus comprising:a discharge chamber;a first electrode positioned in the discharge chamber;a second electrode positioned in the discharge chamber to create an electrode gap having a height extending between the first and second electrode in a first direction and a length extending in a second direction transverse to the first direction between the first electrode and the second electrode; anda plurality of conductive elements electrically connected to the second electrode, each of the plurality of conductive elements extending substantially in the first direction laterally of the electrode gap, the plurality of conductive elements being arranged in a row extending in the second direction, the plurality of conductive elements comprising a first pair of adjacent conductive elements spaced apart in the second direction at a first spacing and a second pair of adjacent conductive elements being spaced apart in the second direction at a second spacing, the second spacing being larger than the first spacing.2. Apparatus as in wherein the conductive elements of the plurality of conductive elements are positioned substantially symmetrically about a midline of the length of the electrode gap.3. An apparatus as in wherein the plurality of conductive elements comprises a first plurality of conductive elements claim 1 , and further comprising a second plurality of conductive elements electrically connected to the second electrode claim 1 , each of the second plurality of conductive elements extending substantially in the first direction laterally of the electrode gap on a side of the electrode gap opposite to the first ...

Laser source unit, control method thereof, photoacoustic image generation apparatus and photoacoustic image generation method

Using a laser source unit, a plurality of wavelengths are switched at a high speed without increasing a rotation speed of a birefringent-filter. A Q switch and a birefringent filter are inserted into an optical resonator including a pair of mirrors facing each other with a laser rod interposed therebetween. The birefringent-filter changes an oscillation wavelength of the optical resonator in association with rotational displacement. Driving unit reciprocatively rotates the birefringent-filter in a predetermined range including a discontinuous point of change characteristics of a transmission wavelength for the rotational displacement. An emission control unit irradiates the laser rod with excitation light from a flash lamp, and then turns on the Q switch at a timing when a rotational displacement position of the birefringent-filter is set to a position corresponding to the wavelength of the pulse laser beam to be emitted, to cause the pulse laser beam to be emitted.

APPARATUS AND METHODS FOR HIGH-SPEED AND LONG DEPTH RANGE IMAGING USING OPTICAL COHERENCE TOMOGRAPHY

Exemplary apparatus can be provided which can include a laser arrangement that is configured to provide a laser radiation, and including an optical cavity. The optical cavity can include a dispersive optical waveguide first arrangement having first and second sides, and which is configured to (i) receive at least one first electro-magnetic radiation at the first side so as to provide at least one second electro-magnetic radiation, and (ii) to receive at least one third electro-magnetic radiation at the second side so as to provide at least one fourth electro-magnetic radiation. The first and second sides are different from one another, and the second and third radiations are related to one another. The optical cavity can also include an active optical modulator second arrangement which can be configured to receive and modulate the fourth radiation so as to provide the first electro-magnetic radiation to the first arrangement. The laser radiation can be associated with at least one of the first, second, third or fourth radiations. 164-. (canceled)65. An apparatus , comprising:a frequency comb optical source;a reference arm configured to provide a first portion of light output by the frequency comb optical source to a reference mirror, and output light reflected from the reference mirror;a sample arm configured to provide a second portion of light output by the frequency comb optical source to a sample, and output light reflected from the sample;a coupler optically coupled to the reference arm and the sample arm, the coupler configured to output a plurality of interference fringes based on the light reflected from the reference mirror and the light reflected from the sample; receive a first interference fringe of the plurality of interference fringes; and', 'output a plurality of components of the first interference fringe;, 'a first optical demultiplexer configured to receive a second interference fringe of the plurality of interference fringes; and', 'output a ...

Mixed-Signal Frequency Control Loop for Tunable Laser

A Lidar system includes a tunable laser configured to generate an output light signal and a photodiode array for receiving light from the tunable laser reflected from a target object. The tunable laser includes a feedback loop including a Mach-Zender interferometer, MZI, receiving the output light signal from the tunable laser, in which the MZI includes two optical paths receiving the output light signal. A phase shifter is provided in one optical path that is operable to produce a pre-determined shift in the phase angle of the light signal passing through the one optical path relative to the phase angle of the light signal passing through the other optical path. A photodiode configured to detect the interference signal generated by the MZI is operable to generate a photodiode current in response thereto. Circuitry converts the photodiode current to a control signal for controlling the tunable laser. 1. A Lidar (light imaging , detection and ranging) system comprising:a tunable laser configured to generate an output light signal; [ a first optical path and a second optical path simultaneously receiving the output light signal; and', 'a phase shifter in the first optical path for providing a pre-determined shift in the phase angle of the light signal passing through said first optical path relative to the phase angle of the light signal passing through said second optical path;, 'a Mach-Zender interferometer (MZI) receiving the output light signal, the MZI including;'}, 'a photodiode configured to detect the interference signal generated by the MZI and generate a photodiode current in response thereto; and', 'circuitry configured and operable to process the photodiode current to generate a control signal for controlling the tunable laser; and, 'a feedback loop including;'}a photodiode array for receiving light from the tunable laser reflected from a target object.2. The Lidar system of claim 1 , wherein the phase shifter is configured to provide a π/2 bias to the ...

FREQUENCY STABILIZED COHERENT BRILLOUIN RANDOM FIBER LASER

A high-finesse Fabry-Perot interferometer (FPI) is introduced into a coherent Brillouin RFL configuration to thereby produce a frequency stabilized random laser. 1. An apparatus comprising:a pump laser,a stimulated Brillouin scattering (SBS) gain fiber for producing stimulated Brillouin Stokes light,a Rayleigh scattering (RS) feedback fiber,a Fabry-Perot interferometer (FPI),wherein the apparatus produces a random laser output from the stimulated Brillouin Stokes light,wherein in the SBS and RS form a coherent Brillouin RFL configuration,wherein the Fabry-Perot interferometer (FPI) is optically connected to the coherent Brillouin RFL configuration, andwherein the Fabry-Perot interferometer (FPI) is configured to frequency stabilize the random laser output by optically interacting with the coherent Brillouin RFL configuration.2. The apparatus of claim 1 , wherein the pump laser has a linewidth of 500 kHz.3. The apparatus of claim 1 , wherein the SBS gain fiber has a length of 2 to 25 km.4. The apparatus of claim 1 , wherein the random laser output has a power of 2.5 to 20 mW.5. The apparatus of claim 1 , wherein the pump laser is a frequency stabilized semiconductor laser (FSSL).6. The apparatus of claim 5 , wherein said FSSL has a linewidth of 500 kHz. This application claims benefit of priority to U.S. Provisional Patent Application No. 61/880,646, filed Sep. 20, 2013 which is incorporated by reference in its entirety.1. Field of the InventionThe present invention relates to random fiber lasers. (RFLs).2. Related ArtDespite its unique characteristics and lasing mechanisms, the field of random fiber lasers (RFLs), which is based on multiple optical scattering in a disordered gain medium, remains young with few realized applications. This is largely due to the lack of lasing directionality which creates difficulty in achieving a stable, high-quality laser in bulk materials.According one broad aspect, the present invention provides an apparatus comprising: a pump ...

SYSTEM, APPARATUS AND METHOD FOR UTILIZING OPTICAL DISPERSION FOR FOURIER-DOMAIN OPTICAL COHERENCE TOMOGRAPHY

An apparatus can be provided which can include a laser arrangement which can be configured to provide a laser radiation, and can include an optical cavity. The optical cavity can include a dispersive optical first arrangement which can be configured to receive and disperse at least one first electro-magnetic radiation so as to provide at least one second electro-magnetic radiation. Such cavity can also include an active optical modulator second arrangement which can be configured to receive and modulate the at least one second radiation so as to provide at least one third electro-magnetic radiation. The optical cavity can further include a dispersive optical third arrangement which can be configured to receive and disperse at least one third electro-magnetic radiation so as to provide at least one fourth electro-magnetic radiation. For example, actions by the first, second and third arrangements can cause a spectral filtering of the fourth electro-magnetic radiation(s) relative to the first electro-magnetic radiation(s). The laser radiation can be associated with the fourth radiation(s), and a wavelength of the laser radiation can be controlled by the spectral filtering caused by the actions by the first, second and third arrangements. 1. An apparatus , comprising: a dispersive optical first arrangement which is configured to receive and disperse at least one first electro-magnetic radiation so as to provide at least one second electro-magnetic radiation,', 'an active optical modulator second arrangement which is configured to receive and modulate the at least one second radiation so as to provide at least one third electro-magnetic radiation, and', 'a dispersive optical third arrangement which is configured to receive and disperse at least one third electro-magnetic radiation so as to provide at least one fourth electro-magnetic radiation,, 'a laser arrangement which is configured to provide a laser radiation, and including an optical cavity which compriseswherein ...

LASER DEVICE, IGNITION SYSTEM, AND INTERNAL COMBUSTION ENGINE

A laser device is provided including a light source configured to emit light, a light transmission member configured to transmit the light emitted from the light source, a plurality of optical elements disposed in an optical path of the light transmitted by the light transmission member, a laser resonator which the light passed through the plurality of optical elements enter, and an adjuster configured to adjust a position of at least one of the plurality of optical elements. 1. A laser device comprising:a light source configured to emit light;a light transmission member configured to transmit the light emitted from the light source;a plurality of optical elements disposed in an optical path of the light transmitted by the light transmission member;a laser resonator which the light passed through the plurality of optical elements enter; andan adjuster configured to adjust a position of at least one of the plurality of optical elements.2. The laser device according to claim 1 , wherein one of the plurality of optical elements is disposed closest to the laser resonator.3. The laser device according to claim 1 , wherein the adjuster adjusts a relative position of the laser resonator.4. The laser device according to claim 1 , wherein the adjuster includes an adjuster to adjust a relative position of at least one of the optical elements and the laser resonator.5. The laser device according to claim 1 , wherein the adjuster includes an adjuster to adjust relative positions of two or more of the optical elements.6. The laser device according to claim 1 , wherein the adjuster includes an adjuster to adjust a relative position of at least one of the optical elements and the light transmission member.7. The laser device according to claim 1 , wherein the light source is a surface emitting laser.8. The laser device according to claim 1 , wherein the laser resonator is a Q-switched laser.9. The laser device according to claim 8 , wherein the laser resonator is made of ceramic. ...

OPTICAL SCANNING AND IMAGING SYSTEMS BASED ON DUAL PULSED LASER SYSTEMS

The invention relates to scanning pulsed laser systems for optical imaging. Coherent dual scanning laser systems (CDSL) are disclosed and some applications thereof. Various alternatives for implementation are illustrated, including highly integrated configurations. In at least one embodiment a coherent dual scanning laser system (CDSL) includes two passively modelocked fiber oscillators. The oscillators are configured to operate at slightly different repetition rates, such that a difference δfin repetition rates is small compared to the values fand fof the repetition rates of the oscillators. The CDSL system also includes a non-linear frequency conversion section optically connected to each oscillator. The section includes a non-linear optical element generating a frequency converted spectral output having a spectral bandwidth and a frequency comb comprising harmonics of the oscillator repetition rates. A CDSL may be arranged in an imaging system for one or more of optical imaging, microscopy, micro-spectroscopy and/or THz imaging. 1. A laser based system for generating optical pulses with a time varying time delay , said system comprising:an optical source, said source comprising: at least one mode locked oscillator, said source generating optical pulses at a time-varying repetition rate, and an output pulse train comprising said pulse pairs derived from said at least one mode locked oscillator propagating in a common optical path, said pulse pairs characterized by having a frequency comb spectrum comprising first and second individual frequency combs, wherein each of said individual frequency combs comprise frequency teeth separated in frequency;a repetition rate modulator configured to modulate said repetition rate at a modulation rate; andan optical element for selecting first and second narrow spectral lines from said first and second combs to monitor at least the carrier envelope offset and repetition rate evolution of said time varying repetition rate.2. The ...

METHOD FOR OPERATING A LASER DEVICE, RESONATOR ARRANGEMENT AND USE OF A PHASE SHIFTER

A method for operating a laser device, including providing a laser pulse in a resonator so that the laser pulse circulates in the resonator, the laser pulse having a carrier wave; determining an offset frequency (f) of the frequency comb corresponding to the laser pulse, the frequency comb having a plurality of laser modes (f) at a distance (f) from one another, the frequencies of which can be described by the formula: f=m*f+f, m being a natural number, and varying the offset frequency (f) by varying a geometric phase (Δφ) that is imparted to the carrier wave of the laser pulse per resonator circulation. 1. Method for operating a laser device comprising the steps of:a) providing a laser pulse in a resonator so that said laser pulse circulates in said resonator, said laser pulse having a carrier wave,{'sub': 0', 'm', 'rep', 'm', 'rep', '0, 'b) determining an offset frequency fof the frequency comb corresponding to said laser pulse, said frequency comb having a plurality of laser modes fat a distance ffrom one another, the frequencies of which can be described by the formula f=m*f+f, m being a natural number, and'}{'sub': '0', 'c) varying said offset frequency fby varying a geometrical phase which imparts a phase circulation delay to said carrier wave of said laser pulse-per resonator circulation.'}2. Method according to claim 1 , wherein varying said geometric phase is performed such that the group circulation time of said laser pulse in said resonator is thereby not changed and fis therefore not or not significantly changed.3. Method according to claim 1 , wherein varying the geometric phase is achieved by varying the orientation claim 1 , in particular by rotation about the optical axis of said resonator claim 1 , of at least a birefringent and/or a polarizing element.4. Method according to claim 3 , wherein steps b) and c) are repeatedly performed consecutively and the nature of the variation of the orientation of said birefringent and/or said polarizing element ...

LASER MODULATION FOR COAGULATION

An apparatus has a pump module providing pump energy, a resonator and a controller. The resonator includes a gain medium receiving the pump energy from the pump module and producing light; reflective surfaces reflecting light produced by the gain medium back toward the gain medium; and a variable light attenuator receiving light produced by the gain medium. The controller controls the amount of light attenuated by the variable light attenuator such that the apparatus emits windows of pulses of laser light at spaced time intervals, each window containing a plurality of pulses of laser light and each interval between windows being larger than an interval between pulses within a window. The emitted windows of pulses of laser light heat tissue to a temperature that causes coagulation without vaporization. 120-. (canceled)21. An apparatus comprising:a pump module providing pump energy; a gain medium receiving the pump energy from the pump module and producing light;', 'at least two at least partially reflective surfaces reflecting light produced by the gain medium back toward the gain medium;', 'a variable light attenuator receiving light produced by the gain medium;, 'a resonator comprisinga controller that provides a driver signal to the variable light attenuator to control the amount of light attenuated by the variable light attenuator such that the apparatus emits windows of pulses of laser light at spaced time intervals, each window containing a plurality of pulses of laser light and each interval between windows being larger than an interval between pulses within a window, the duration of the windows and the duration of the intervals between windows being such that the emitted windows of pulses of laser light heat tissue to a temperature that causes coagulation, wherein the provided driver signal is at a first magnitude during the intervals between windows, transitions to a second magnitude to cause the apparatus to emit a first pulse of laser light of a window, ...

Solid-state laser device

Provided is a solid-state laser device in which a linear resonator including an output mirror and a rear mirror, a laser rod, and optical members are provided on a common base and are contained in a housing having the base as a portion. A holding part is provided to hold an excitation light source that extends parallel to the laser rod on a side of the laser rod opposite to the base. The optical members including a Q-switch are disposed between the laser rod and the rear mirror. An upper end position of the output mirror is at a position lower than a lower end position of the excitation light source held by the holding part, with the base as a reference. The holding part holds the excitation light source so as to be capable of being inserted and extracted with respect to the output mirror side in a longitudinal direction of the excitation light source.

EMBEDDED MICROFLUIDIC DISTRIBUTION APPARATUS FOR PASSIVELY COOLING OPTOELECTRONIC DEVICES

A device and method are provided for more efficient thermal management of optoelectronic devices. A microfluidic distribution apparatus embedded with the optoelectronic device uses a working fluid in phase change to passively remove heat from an optoelectronic device. The working fluid undergoes phase change through various conversions between a liquid state and a two-phase liquid-vapor state to facilitate evaporation and condensation processes as the working fluid is distributed through micro-structures in the embedded microfluidic distribution apparatus. Passive two-phase cooling provides high thermal performance due to the use of the latent heat of a fluid in phase change, as well as the presence of favorable two-phase flow regimes at micro-scale dimensions. 1. An apparatus for cooling an optoelectronic device , comprising: distributing the working fluid in a liquid state through the plurality of micro-structures, wherein the working fluid converts to a two-phase liquid-vapor state to remove heat generated by the optoelectronic device via an evaporation process; and', 'further distributing the working fluid in the two-phase liquid-vapor state through the plurality of micro-structures to passively dissipate heat to air in natural convection via a condensation process, wherein the working fluid converts from the two-phase liquid-vapor state back to the liquid state for recirculation via the plurality of micro-structures., 'a microfluidic distribution apparatus positioned in an embedded arrangement with the optoelectronic device, the microfluidic distribution apparatus including a plurality of micro-structures forming a closed loop fluid distribution circuit, the microfluidic distribution apparatus being configured to distribute a working fluid capable of phase change to passively remove heat from the optoelectronic device by2. The apparatus according to claim 1 , wherein the microfluidic distribution apparatus comprises:an evaporator section having one or more ...

CONTROL OF A SPECTRAL FEATURE OF A PULSED LIGHT BEAM

A spectral feature of a pulsed light beam produced by an optical source is controlled by a method. The method includes producing a pulsed light beam at a pulse repetition rate; directing the pulsed light beam toward a substrate received in a lithography exposure apparatus to expose the substrate to the pulsed light beam; modifying a pulse repetition rate of the pulsed light beam as it is exposing the substrate. The method includes determining an amount of adjustment to a spectral feature of the pulsed light beam, the adjustment amount compensating for a variation in the spectral feature of the pulsed light beam that correlates to the modification of the pulse repetition rate of the pulsed light beam. The method includes changing the spectral feature of the pulsed light beam by the determined adjustment amount as the substrate is exposed to thereby compensate for the variation in the spectral feature. 1. A method of controlling a spectral feature of a pulsed light beam produced by an optical source , the method comprising:producing, from the optical source, a pulsed light beam at a pulse repetition rate;directing the pulsed light beam toward a substrate received in a lithography exposure apparatus to expose the substrate to the pulsed light beam;receiving an instruction to modify a pulse repetition rate of the pulsed light beam as the pulsed light beam is exposing the substrate;modifying the pulse repetition rate of the pulsed light beam as it is exposing the substrate based on the received instruction;determining a variation in the spectral feature of the pulsed light beam that correlates with the modification of the pulse repetition rate of the pulsed light beam;determining an amount of adjustment to a spectral feature of the pulsed light beam, the adjustment amount compensating for the determined variation in the spectral feature of the pulsed light beam that correlates to the modification of the pulse repetition rate of the pulsed light beam; andcompensating for ...

THERMO-OPTIC INTRACAVITY BEAM SHAPING AND MODE CONTROL WITH DOPED OPTICAL MATERIALS

A laser beam shaping system which has a laser resonator configured to operate at a resonating, first wavelength range to produce an intracavity resonating beam and a laser gain material, configured to produce gain and to amplify the first wavelength range within the laser resonator. The system has at least one doped medium, which is optically transparent at the first wavelength range, which is doped with a dopant, and which is provided intracavity in the laser resonator and at least one absorbed beam input or coupling configured to generate or receive at least one absorbed beam at a second wavelength range which is different from the first wavelength range and which is directed towards the doped medium. The doped medium has a higher absorption characteristic at the second wavelength range than at the first wavelength range, causing the absorbed beam to have a higher absorption than the resonating beam in the doped medium, but which does not provide gain in the first wavelength range. Optical surfaces of the doped medium are coated to be anti-reflective at the first wavelength range and highly transmissive at the second wavelength range. 1. A laser beam shaping system which includes:a laser resonator configured to operate at a resonating, first wavelength range to produce an intracavity resonating beam;a laser gain material, configured to produce gain and to amplify the first wavelength range within the laser resonator;at least one doped medium, which is optically transparent at the first wavelength range, which is doped with a dopant, and which is provided intracavity in the laser resonator;at least one absorbed beam input or coupling configured to generate or receive at least one absorbed beam at a second wavelength range which is different from the first wavelength range and which is directed towards the doped medium,wherein the doped medium has a higher absorption characteristic at the second wavelength range than at the first wavelength range, causing the ...

LASER WAVELENGTH CENTER LOCK USING PHOTONIC INTEGRATED CIRCUIT

An apparatus includes an optical splitter configured to receive an optical signal and to split the input optical signal to provide a first and a second optical signal. The apparatus further includes an interferometer comprising a first arm and a second arm, with the first arm being configured to receive the first optical signal, and the second arm being configured to receive the second optical signal. Notably a portion of the first arm is exposed to a reference gas that attenuates light of a characteristic wavelength. The apparatus further includes an optical coupler configured to receive an output optical signal from the first arm, and an output optical signal from the second arm and to provide a third optical signal; and a photodetector configured to receive the third optical signal, and to provide a photocurrent. The photocurrent increases when the difference between the characteristic wavelength and the wavelength of the optical signals increases. The apparatus also comprises a feedback control circuit configured to change the properties of the laser to be locked until an error signal indicative of the difference between the characteristic wavelength and the wavelength of the laser is substantially zero. 1. An apparatus for locking a wavelength of a laser , the apparatus comprising:an optical splitter configured to receive an optical signal and to split an input optical signal to provide a first and second optical signal;an interferometer comprising a first arm and a second arm, the first arm being configured to receive the first optical signal and the second arm being configured to receive the second optical signal, wherein a portion of the first arm is exposed to a reference gas that attenuates light of a characteristic wavelength;an optical coupler configured to receive an output optical signal from the first arm, and an output optical signal from the second arm and to provide a third optical signal;a photodetector configured to receive the third optical ...

METHOD FOR PRESERVING THE SYNCHRONISM OF A FOURIER DOMAIN MODE LOCKED (FDML) LASER

The invention relates to a method for maintaining the synchronism of a Fourier Domain Mode Locked (FDML) laser, the FDML laser comprising at least one dispersion-compensated resonator with at least one variably wavelength-selective optical filter, the laser light circulating in the resonator at a circulation frequency, and the wavelength selectivity of the filter being repeatedly modified at a syntonising rate, the FDML laser being synchronous when the syntonising rate is an integral multiple of the circulation frequency. Said method is characterised by the following steps: a) at least a portion of the laser light is coupled out of the resonator; b) at least a portion of the decoupled laser light is detected by means of a photodetector; c) amplitudes in the measuring signal of the photodetector are counted during successive counting intervals; and d) the circulation frequency or syntonising rate is adjusted such that the ratios of the count value to the lengths of the counting intervals are maintained within a predetermined nominal value interval. 1. A method for preserving the synchronism of a Fourier Domain Mode Locked (FDML) laser , wherein the FDML laser comprises at least one dispersion-compensated resonator having at least one variable wavelength-selective optical filter , wherein the laser light circulates in the resonator with a round-trip frequency and the filter is repeatedly altered in its wavelength selectivity with a tuning rate , wherein the FDML laser is synchronized when the tuning rate is an integer multiple of the round-trip frequency , the method comprising:a. outcoupling of at least one portion of the laser light from the resonator;b. detecting at least one portion of the outcoupled laser light with at least one photodetector;c. counting the deflections in the measurement signal of the photodetector during consecutive counting time intervals;d. controlling the round-trip frequency or tuning rate such that the ratios of the count values to the ...

EXTERNAL CAVITY TUNABLE LASER WITH DUAL BEAM OUTPUTS

The invention relates to an external cavity tunable laser with dual beam outputs. The first laser cavity of the tunable laser comprises a first laser cavity mirror, a laser gain medium, an intracavity collimating lens, an active optical phase modulator, a tunable acousto-optic filter, a tunable Fabry-Perot tunable filter, a second reflection mirror all disposed inside a laser cavity sequentially, and a laser driver and control system. The laser cavity beam reflected by the first laser cavity mirror enters the tunable acousto-optic filter to generate a zeroth order diffracted beam as the first laser output beam. The laser cavity beam reflected by the second laser cavity mirror enters the tunable acousto-optic filter to generate a zeroth order diffracted beam as the second laser output beam. The tunable laser further comprises a wavelength locker outside the laser cavity. The second laser cavity of the tunable laser has a Fabry-Perot etalon disposed in the first laser cavity to further compress the spectrum width of the laser output beams. The invention is compact with high performance without mechanical moving parts, stable laser output, low cost for volume production and installation. 1. An external cavity tunable laser with dual beam outputs comprisinga first laser cavity mirror, a laser gain medium, an intracavity collimating lens, an active optical phase modulator, a tunable acousto-optic filter, a tunable Fabry-Perot filter, a second laser cavity mirror and a laser drive and control system;the tunable Fabry-Perot filter includes a first reflection mirror, a liquid crystal phase modulator, and a second reflection mirror; the first reflection mirror, and the second reflection mirror forms a Fabry-Perot cavity, the liquid crystal phase modulator is disposed inside the Fabry-Perot cavity;the intracavity collimating lens collimates the light beam outputted from the laser gain medium and inputs the collimated beam into the tunable acousto-optic filter at Bragg angle ...

Ultra-low noise mode-locked laser, methods, and applications

A mode-locked laser (MLL) that produces ultra-low phase noise optical and RF outputs, includes two nested resonant optical cavities including an optical fiber-based cavity and an etalon, and a three bandwidth Pound-Drever-Hall (PDH) frequency stabilizer assembly incorporating three different optical bandpass filters. The optical fiber-based cavity is characterized by a free spectral range, FSR, and the etalon is characterized by a free spectral range, FSR, wherein FSR/FSRis an integer equal to or greater than 2. A method of generating ultra-low phase noise optical and RF outputs is disclosed. Optical and RF outputs have a phase noise that is less than −100 dBc/Hz at 1 Hz and less than −150 dBc at 10 KHz. 1. A mode-locked laser (MLL) that produces ultra-low phase noise optical and RF outputs , comprising: at least one optical fiber-based cavity, and', 'at least one periodic frequency filter cavity; and, 'a plurality of nested resonant cavities including{'sub': L', 'H', 'C, 'a three bandwidth Pound-Drever-Hall (PDH) frequency stabilizer assembly that includes at least three different optical bandpass filters, f, f, f, corresponding to a low frequency, a high frequency, and a center frequency, respectively, of an optical output spectrum of the MLL,'}{'sub': 'fiber', 'wherein the at least one optical fiber-based cavity is characterized by a free spectral range, FSR, and'}{'sub': 'filter', 'wherein the at least one periodic frequency filter cavity is characterized by a free spectral range, FSR,'}{'sub': filter', 'fiber, 'further wherein FSR/FSRis an integer equal to or greater than 2.'}2. The MML of claim 1 , wherein the at least one optical fiber-based cavity further includes:a semiconductor optical amplifier (SOA), anda harmonic mode locker component.3. The MML of claim 2 , wherein the harmonic mode locker component is at least one of an active harmonic mode locker claim 2 , a passive harmonic mode locker claim 2 , and a combination (hybrid) active/passive harmonic ...

Polarization-Maintaining Fiber Laser Tunable Over Two Micron Region

A wavelength-tunable, polarization-maintaining (PM) fiber laser for use in the two micron wavelength region is based upon a ring laser geometry and includes sections of polarization-maintaining (PM) optical fiber for supporting propagation of the circulating laser radiation around the ring. At least one gain module is included in the ring and is formed of polarization-maintaining active optical fiber including a core region that is doped with either Thulium (Tm) or Holmium (Ho), or co-doped with both of these rare earth materials. In the presence of a pump beam operating at a suitable wavelength, the gain module(s) generate laser radiation at a wavelength within the two micron region. A PM-based tunable bandpass filter (BPF) is included within the ring and used to control/adjust the wavelength of the output beam provided by the fiber laser.

Femtosecond pulse laser apparatus

A femtosecond pulse laser apparatus includes a pump light source configured to provide a pump light, a gain medium configured to obtain a gain of a laser light using the pump light, a first curved mirror and a second curved mirror, which are provided at both sides of the gain medium, an output mirror configured to transmit a portion of the laser light and reflect the other portion of the laser light to the gain medium, a mode locking portion configured to generate a femtosecond pulse of the laser light, and an acoustic wave generator configured to provide an acoustic wave into the gain medium so as to adjust self-phase modulation of the laser light.

HIGH-PEAK-POWER SINGLE-FREQUENCY NARROW-LINEWIDTH NANOSECOND FIBER LASER BASED ON A TRIANGULAR PULSE

The present invention discloses a high-peak-power single-frequency narrow-linewidth nanosecond fiber laser based on a triangular pulse, wherein the laser includes: pulsed laser generated by the laser seed injecting into a first power pre-amplifier through a first isolator, and then injecting into a second pre-amplifier and then injecting into a power amplifier; wherein triangle-shaped pulsed laser with fast rising edge is obtained by using electro-optic and acousto-optic modulator to modulate continuous wave single-frequency laser or a single-frequency semiconductor laser directly modulated by radio frequency signal; single-frequency triangle-shaped pulsed laser is employed as the laser source according to the characteristics of narrow intrinsic linewidth and suppression of linewidth broadening caused by SPM, and the power of pulsed laser is amplified through the MOPA system. 1. A high-peak-power single-frequency narrow-linewidth nanosecond fiber laser based on a triangular pulse , wherein the laser includes:pulsed laser generated by the laser seed injecting into a first power pre-amplifier through a first isolator, and then injecting into a second pre-amplifier and then injecting into a power amplifier;wherein triangle-shaped pulsed laser with fast rising edge is obtained by using electro-optic and acousto-optic modulator to modulate continuous wave single-frequency laser or a single-frequency semiconductor laser directly modulated by radio frequency signal;single-frequency triangle-shaped pulsed laser is employed as the laser source according to the characteristics of narrow intrinsic linewidth and suppression of linewidth broadening caused by SPM, and the power of pulsed laser is amplified through the MOPA system.2. The high-peak-power single-frequency narrow-linewidth nanosecond pulsed fiber laser based on a triangular pulse according to claim 1 , wherein the first power pre-amplifier includes a first pumping source claim 1 , a first combiner claim 1 , a first ...

Laser source unit and photoacoustic image generation apparatus

A laser source unit obtains Q switch pulse oscillation with a simple structure while continuously switching a plurality of wavelengths. A laser source unit emits pulsed laser beams with a plurality of different wavelengths. A flash lamp radiates excitation light to a laser rod. A pair of mirrors face each other with the laser rod interposed therebetween. The pair of mirrors form an optical resonator. Wavelength selection unit controls the wavelength of light which resonates in the optical resonator to any one of a plurality of wavelengths to be emitted by the laser source unit. Driving unit drives the wavelength selection unit such that the optical resonator performs the Q switch pulse oscillation.

Wavelength Stabilized Diode Laser

A hybrid external cavity laser and a method for configuring the laser having a stabilized wavelength is disclosed. The laser comprises a semiconductor gain section and a volume Bragg grating, wherein a laser emission from the semiconductor gain section is based on a combination of a reflectivity of a front facet of the semiconductor gain section and a reflectivity of the volume Bragg grating and the reflectivity of the semiconductor gain section and the volume Bragg grating are insufficient by themselves to support the laser emission. The hybrid cavity laser further comprises an etalon that provides further wavelength stability. 1. A device for generating a laser emission having a stable wavelength , the device comprising:a semiconductor gain section having a light emission of a known non-lasing peak wavelength and a known spectral width, said semiconductor gain section comprising:a rear facet having a first reflectivity; anda front facet having a second reflectivity, said rear facet and said front facet forming a first resonant cavity having a first plurality of resonances within the spectral width of the light emission of said semiconductor gain section,an optics section collecting and collimating said light emission; and receiving said collected and collimated light emission, and', 'reflecting a portion of the received collected and collimated light emission back into the semiconductor gain section, wherein the rear facet of the semiconductor gain section and the volume Bragg grating form a second resonant cavity with a second plurality of resonant wavelengths,, 'a volume Bragg grating, having a known reflectivity, said volume Bragg gratingwherein one of said first plurality of resonances and one of said second plurality of resonant wavelengths is substantially coincident and said laser emission is emitted at said substantially coincident wavelength when a sum of a reflected portion of the collected and collimated light emission from the volume Bragg grating and ...

Fast phase-shift interferometry by laser frequency shift

An acousto-optic modulator (AOM) laser frequency shifter system includes a laser configured to generate an incident beam, a first optical splitter optically coupled to the laser and configured to split the incident beam into at least one portion of the incident beam, at least one phase-shift channel optically coupled to the first optical splitter and configured to generate at least one frequency-shifted beam with an acousto-optic modulator (AOM) from the at least one portion of the incident beam received from the first optical splitter, and a second optical splitter configured to receive the at least one frequency-shifted beam from the at least one phase-shift channel and configured to direct the at least one frequency-shifted beam to an interferometer configured to acquire an interferogram of a sample with the at least one frequency-shifted beam.

LASER LIGHT-SOURCE APPARATUS AND LASER PULSE LIGHT GENERATING METHOD

A laser light-source apparatus includes a control unit configured to perform control in such a manner that a seed light source is driven in a pulse oscillation mode of oscillating pulse light based on gain switching in an output permitted state where output of pulse light from the apparatus is permitted, and is driven in a continuous oscillation mode of oscillating continuous light in an output stopped state in which the output of the pulse light from the apparatus is stopped, with power of excitation light for a solid state amplifier maintained, and adjusts power of laser light input to the solid state amplifier from the seed light source in the continuous oscillation mode in such a manner that the solid state amplifier outputs light with substantially same average power in the output stopped state and in the output permitted state. 1. A laser light-source apparatus comprising:a seed light source configured to output pulse light based on gain switching;an amplifier configured to amplify the pulse light output from the seed light source; anda control unit configured to perform control in such a manner that the seed light source is driven in a pulse oscillation mode of oscillating the pulse light based on the gain switching in an output permitted state where output of the pulse light from the laser light-source apparatus is permitted, and is driven in a continuous oscillation mode of oscillating continuous light in an output stopped state in which the output of the pulse light from the laser light-source apparatus is stopped, with power of excitation light for the amplifier maintained, and to adjust power of laser light input to the amplifier from the seed light source in the continuous oscillation mode in such a manner that the amplifier outputs light with substantially same average power in the output stopped state and in the output permitted state.2. The laser light-source apparatus according to claim 1 ,wherein the amplifier at least includes a solid state ...

ELECTRIC POWER TRANSFER SYSTEM USING OPTICAL POWER TRANSFER

An apparatus and method for optical-power-transfer (OPT). A light source converts electrical energy into light, and the light is transmitted from the active layer of the light source directly to the active layers of a series of photovoltaic (PV) devices without first passing through a conduction layer of the PV device. Thus, absorption in the conduction layer is avoided, and the efficiency of the OPT system is improved. The PV devices are configured to each generate equal current, and the PV devices are electrically connected in series. PV devices are arranged in series with light first propagating through PV devices closer to the light source, and farther PV devices having a longer propagation length, such that the light absorbed and current generated by each PV device is equal to the other PV devices. In one implementation, the PV devices are configured in a laser cavity with the light source. 1. An optical-power-transfer (OPT) apparatus , comprising:a first optical resonator;a first light source configured to convert electrical energy to light, the first light source including an active region arranged to overlap an optical mode of the first optical resonator; anda first photovoltaic device including an active region arranged to overlap an optical mode of the first optical resonator and configured to convert light to electrical energy, whereinthe first optical resonator is configured to lase when a round-trip gain including gain from the active region of the first light source is greater than a round-trip loss including absorption by the active region of the first photovoltaic device.2. The OPT apparatus according to claim 1 , further comprising:a plurality of optical resonators including the first optical resonator;a plurality of light sources including the first light source, each of the light sources including an active region arranged to overlap an optical mode of the respective optical resonator of the plurality of optical resonators.3. The OPT apparatus ...

ELECTRO-OPTIC MODULATOR

An electro-optic modulator (EOM) for altering an optical path length of an optical field is described. The EOM comprises first and second Brewster-angle cut nonlinear crystals having a first and second optical axis. The optical axes are orientated relative to each other such that when an optical field propagates through the nonlinear crystals it experiences no overall deviation. The nonlinear crystals are also arranged to be opposite handed relative to the optical field. The EOM has the advantage that its optical losses are lower when compared with those EOMs known in the art. In addition, the EOM can be inserted into, or removed from, an optical system without any deviation being imparted onto the optical field. This reduces the levels of skill and effort required on the part of an operator. The described method and apparatus for mounting the nonlinear crystals also suppresses problematic piezo-electric resonances within the nonlinear crystals. 1. An electro-optic modulator (EOM) suitable for altering an optical path length of an optical field , the electro-optic modulator (EOM) comprising:a first Brewster-angle cut nonlinear crystal having a first light input axis and a first light output axis;a second Brewster-angle cut nonlinear crystal having a second light input axis and a second light output axis, wherein the first light output axis is coincident with the second light input axis between the first and second Brewster-angle cut nonlinear crystals; and the first and second Brewster-angle cut nonlinear crystals are arranged to be opposite handed relative to the optical field propagating through the first and second Brewster-angle cut nonlinear crystals;a mounting apparatus that provides a means for locating the first and/or second Brewster-angle cut nonlinear crystals, the mounting apparatus comprising a first clamp section having one or more adjustable crystal holders and a first electrically insulating base plate attached to the first clamp section; anda layer ...

Q-SWITCHED LASER SYSTEM

A laser system, comprising: a laser cavity, a gain medium positioned within the laser cavity, a pump source optically coupled to the gain medium, an input minor positioned at a first end of the laser cavity, an output coupler positioned at a second end of the laser cavity, a first etalon positioned within the laser cavity, and a q-switching element positioned within the laser cavity, wherein the laser system is configured to provide a laser beam at a selected wavelength ranging of 1700 to 3000 nm with a tunable spectral range of at least 10 nm. A method for using the laser system e.g., for producing a pulsed laser beam is further disclosed. 1. A laser system , comprisinga laser cavity;a gain medium positioned within the laser cavity;a pump source optically coupled to the gain medium;an input mirror positioned at a first end of the laser cavity;an output coupler positioned at a second end of the laser cavity;a first etalon positioned within the laser cavity;and a q-switching element positioned within the laser cavity;wherein:the laser system is configured to provide a pulsed laser beam at a selected wavelength ranging of 1700 to 3000 nm with a tunable spectral range of at least 10 nm;the q-switching element provides a pulse switching of a laser beam;and wherein the gain medium, the pump source, the input mirror, the output coupler, the first etalon, and the q-switching element are at a light-pass of the pulsed laser beam.2. The laser system of claim 1 , further comprising a second etalon at a light-pass of the pulsed laser beam claim 1 , positioned next to the first etalon.3. The laser system of any one of and claim 1 , wherein the first and/or the second etalon comprises Yttrium Aluminum Garnet YAlO(YAG).4. The laser system of any one of and claim 1 , wherein the second etalon is characterized by a thickness of 100 to 600 μm.5. The laser system any one of to claim 1 , wherein the first etalon is characterized by a thickness of 10 to 100 μm.6. The laser system of any ...

Method and apparatus for locking and scanning the output frequency from a laser cavity

A tunable reference cavity ( 3 ) with two independently controllable mirrors ( 15, 16 ) is disclosed. The mirrors are mounted on respective piezoelectric crystals ( 18, 19 ) so that thermal expansion of the piezoelectric crystals moves the cavity mirrors in the same direction along a longitudinal axis of the reference cavity thereby reducing a change of the cavity length. Also disclosed is a system for locking and scanning the output of a laser cavity ( 2 ). An error signal is generated between an output of the laser cavity ( 28 ) and the transmission ( 28 ) of the laser through the external reference cavity ( 3 ). A dual piezo-actuated mirror ( 6 b ) permits processing of the error signal ( 26 ) with separate signal processing circuits ( 29 a, 29 b ) used to provide an electrical feedback signal to the dual piezoelectric crystal ( 22, 23 b ).

METHOD AND APPARATUS FOR LOCKING AND SCANNING THE OUTPUT FREQUENCY FROM A LASER CAVITY

A system and method that can be employed to lock and scan the output of a laser cavity () is described. The system and method involves the use of a signal generator for generating an error signal between an output of the laser cavity () and the transmission () of the laser through a tunable external reference cavity (). A dual piezo-actuated mirror () permits processing of the error signal () with separate signal processing circuits () used to provide an electrical feedback signal to the two piezo electric crystals (). When incorporated within a laser cavity the described system and methodology can be used to lock and scan the output of the laser cavity while providing the laser output with a reduced linewidth. 1. A locking and scanning apparatus for a laser cavity the apparatus comprising an external reference cavity and a locking and scanning circuit electrically connected to a dual piezo-actuated mirror of the laser cavity wherein the circuit comprises:a signal generator for generating an error signal between an output from the laser cavity and an output from the external reference cavity and splitting the error signal into a first and second component;a first signal processing circuit for processing the first component of the error signal to provide a feedback signal for a first piezoelectric crystal of the dual piezo-actuated mirror; anda second signal processing circuit for processing the second component of the error signal to provide a feedback signal for a second piezoelectric crystal of the dual piezo-actuated mirror.2. A locking and scanning apparatus as claimed in wherein the thickness of the second piezoelectric crystal of the dual piezo-actuated mirror is less than the thickness of the first piezoelectric crystal.3. A locking and scanning apparatus as claimed in wherein a configuration of second piezoelectric crystal of the dual piezo-actuated mirror is such that it can be driven at a higher frequency than the first piezoelectric crystal of the dual ...

Laser stabilization with an actively controlled fabry-perot resonance cavity

Tuning of an optical resonator, e.g., a Fabry-Perot resonant etalon, is carried out. The length of the resonator is actively controlled through the frequency of an identical length microwave resonant cavity. The length is tunable over a several micron range with the precision and stability of the microwave source frequency.

WAVELENGTH BEAM COMBINING LASER SYSTEMS UTILIZING ETALONS

In various embodiments, wavelength beam combining laser systems incorporate etalons to establish external lasing cavities and/or to combine multiple input beams into a single output beam. 1. A laser system comprising:an array of beam emitters each emitting a beam, the beams being emitted substantially parallel to each other in a propagation direction;an etalon for receiving the beams and combining the beams into a multi-wavelength beam, the etalon having an optical axis tilted at a non-zero angle with respect to the propagation direction;disposed optically downstream of the beam emitters and optically upstream of the etalon, focusing optics for focusing the beams toward the etalon; anda partially reflective output coupler for receiving the multi-wavelength beam, reflecting a first portion thereof back toward the etalon, and transmitting a second portion thereof as an output beam composed of multiple wavelengths, a partially reflective front surface for receiving the beams, and', 'a back surface having (i) a reflective portion for reflecting the beams back toward the front surface, and (ii) an exit portion from which the multi-wavelength beam exits the etalon, one or more of the beams being reflected by both the front surface and the reflective portion of the back surface prior to combination into the multi-wavelength beam., 'wherein the etalon comprises2. The laser system of claim 1 , wherein a reflectivity of the front surface of the etalon to the beams is greater than approximately 75% but less than 100%.3. The laser system of claim 1 , wherein the reflective portion of the back surface of the etalon has a reflectivity to the beams of approximately 100%.4. The laser system of claim 1 , further comprising collimation optics disposed optically downstream of the etalon and optically upstream of the partially reflective output coupler.5. The laser system of claim 1 , wherein the exit portion of the back surface of the etalon comprises an anti-reflective coating ...

APPARATUS FOR EMITTING LASER PULSES

A laser resonator includes a gain medium that produces light from pump energy and a variable light attenuator, which receives light and emits either (i) a first light including a continuous series of micropulses, or (ii) a second light including a series of macropulses at spaced time intervals, where each macropulse includes a series of micropulses. Each micropulse has a duration of 0.1 to 10 microseconds, and a duration of each macropulse is less than the time interval between each macropulse, and the micropulses have a frequency of 5 kHz to 40 kHz. 120-. (canceled)21. A laser apparatus comprising:a pump module configured to provide a pump energy; and a gain medium configured to produce a light from the pump energy;', 'a variable light attenuator that receives the light; and', a first mode, wherein a first light including a continuous series of micropulses is emitted from the laser apparatus; and', 'a second mode, wherein a second light including a series of macropulses at spaced time intervals is emitted from the laser apparatus, wherein each macropulse includes a series of micropulses, wherein each successive one of the macropulses has a magnitude greater than a magnitude of a preceding macropulse, and the micropulses have a frequency of 5 kHz to 40 kHz., 'a controller configured to switch the variable light attenuator between], 'a laser resonator comprising22. The apparatus of claim 21 , further comprising an optical coupler configured to introduce the first and/or second light into an optical fiber.23. The apparatus of claim 22 , wherein the optical fiber includes a side-firing delivery tip.24. The apparatus of claim 21 , wherein the controller is configured to respond to one or more input devices operable to switch the variable attenuator between the first and second modes.25. The apparatus of claim 21 , wherein the controller further includes:a driver configured to produce a driver signal, the driver having an input for turning the driver signal on and off, ...

METHOD FOR CONTROLING WAVELENGTH TUNABLE LASER, AND WAVELENGTH TUNABLE LASER

A lasing wavelength is controlled so that a wavelength detection result becomes a first target value; selection is made to select either a step of calculating a second target value as a wavelength detection result with a shift of the lasing wavelength, or a step of calculating a third control value of a wavelength characteristic of an etalon for letting a laser lase at a wavelength with a shift of the lasing wavelength; in the former step, the lasing wavelength is controlled so that the wavelength detection result becomes the second target value; in the latter step, the lasing wavelength is controlled so that the wavelength detection result becomes the first target value. 1. A method for controlling a wavelength tunable laser having a wavelength detection unit including an etalon , the method comprising:a first step of acquiring information of a first control value to define a wavelength characteristic of the etalon in the drive condition corresponding to a first wavelength, a first target value of the wavelength detection unit corresponding to the first wavelength, a value of a second wavelength different from the first wavelength, and a value of a shift amount;a second step of calculating a second control value from the first control value to define a wavelength characteristic of the etalon to acquire the second wavelength when the wavelength detection unit detects the first target value;a third step of selecting eitherA) shifting wavelength of the laser by changing the first target value to a second target value corresponding to the shift amount, orB) shifting wavelength of the laser by changing the second control value of the wavelength characteristics of the etalon to a third control value of the wavelength characteristics of the etalon corresponding to the shift amount; anda fourth step of driving the laser by using eitherA) second control value of the wavelength characteristics of the etalon, and the second target value, orB) third control value of the ...

SYSTEM, APPARATUS AND METHOD FOR UTILIZING OPTICAL DISPERSION FOR FOURIER-DOMAIN OPTICAL COHERENCE TOMOGRAPHY

An apparatus can be provided which can include a laser arrangement which can be configured to provide a laser radiation, and can include an optical cavity. The optical cavity can include a dispersive optical first arrangement which can be configured to receive and disperse at least one first electro-magnetic radiation so as to provide at least one second electro-magnetic radiation. Such cavity can also include an active optical modulator second arrangement which can be configured to receive and modulate the at least one second radiation so as to provide at least one third electro-magnetic radiation. The optical cavity can further include a dispersive optical third arrangement which can be configured to receive and disperse at least one third electro-magnetic radiation so as to provide at least one fourth electro-magnetic radiation. For example, actions by the first, second and third arrangements can cause a spectral filtering of the fourth electro-magnetic radiation(s) relative to the first electro-magnetic radiation(s). The laser radiation can be associated with the fourth radiation(s), and a wavelength of the laser radiation can be controlled by the spectral filtering caused by the actions by the first, second and third arrangements. 1. An apparatus , comprising: a dispersive optical first arrangement which is configured to receive and disperse at least one first electro-magnetic radiation so as to provide at least one second electro-magnetic radiation,', 'an active optical modulator second arrangement which is configured to receive and modulate the at least one second radiation so as to provide at least one third electro-magnetic radiation, and', 'a dispersive optical third arrangement which is configured to receive and disperse at least one third electro-magnetic radiation so as to provide at least one fourth electro-magnetic radiation,, 'a laser arrangement which is configured to provide a laser radiation, and including an optical cavity which compriseswherein ...

Laser device

A frequency tuneable laser device includes a cavity mode selector and a cavity tuning arrangement. The cavity mode selector has a frequency response with a selection feature that is alignable in frequency with a selected cavity mode of the laser device. The cavity tuning arrangement includes a plurality of reflective elements arranged in optical series, and is used to adjust the effective optical path length of the laser cavity to move the cavity modes in frequency. The laser device further includes making the cavity mode selector and the cavity tuning arrangement perform a simultaneous coordinated movement such that respective frequencies of the selection feature and the selected cavity mode vary with substantially the same dependence on a parameter characterising the simultaneous coordinated movement. For example, a periscope with a co-rotating etalon can be used to provide mode hop free tuning of the laser device.

TUNABLE SOI LASER

A wavelength tunable silicon-on-insulator (SOI) laser comprising: a laser cavity including: a semiconductor gain medium having a front end and a back end, wherein a mirror of the laser cavity is located at the back end of the semiconductor gain medium; and a phase-tunable waveguide platform coupled to the front end of the semiconductor gain medium, the phase-tunable waveguide platform comprising: a first resonator and a second resonator; at least one resonator being a phase-tunable resonator; wherein the first resonator is any one of: an MMI device including a pair of reflective surfaces defining a resonator cavity therebetween such that the device is configured to act as a Fabry-Perot filter; a ring resonator; or a waveguide Fabry-Perot filter; and wherein the second resonator is any one of: an MMI device including a pair of reflective surfaces defining a resonator cavity therebetween such that the device is configured to act as a Fabry-Perot filter; a ring resonator; or a waveguide Fabry-Perot filter. 1. A wavelength tunable silicon-on-insulator (SOI) laser comprising:a laser cavity including:a semiconductor gain medium having a front end and a back end; and a first waveguide Fabry-Perot filter; and', 'a second waveguide Fabry-Perot filter, at least one of the Fabry-Perot filters being a phase-tunable Fabry-Perot filter,, 'a phase-tunable waveguide platform coupled to the front end of the semiconductor gain medium, the phase-tunable waveguide platform comprisingwherein a mirror of the laser cavity is located at the back end of the semiconductor gain medium.2. The wavelength tunable SOI laser of claim 1 , wherein the first and second Fabry-Perot filters are formed by a total of three cascaded Distributed Bragg Reflector (DBR) gratings.3. The wavelength tunable SOI laser of claim 1 , wherein the first and second Fabry-Perot filters are formed by a total of three waveguide partial reflectors.4. The wavelength tunable SOI laser of claim 1 , wherein the phase-tunable ...

SURFACE EMITTING LASER AND OPTICAL COHERENCE TOMOGRAPHY APPARATUS

A surface emitting laser is provided which requires a smaller number of components, and which can reduce the cost. 1. A surface emitting laser comprising:a first reflecting mirror;a second reflecting mirror;an active layer disposed between the first reflecting mirror and the second reflecting mirror;a third reflecting mirror arranged on an opposite side of the active layer with respect to the second reflecting mirror; anda light receiving element arranged to receive light passing through the third reflecting mirror,wherein the surface emitting laser having a resonant wavelength changed with movement of the first reflecting mirror relative to the second reflecting mirror,wherein the second reflecting mirror and the third reflecting mirror constitute an etalon so that transmittance of the etalon varies at a certain period of an optical frequency within a range of a wavelength emitted by the surface emitting laser.2. The surface emitting laser according to claim 1 , wherein the surface emitting laser constitutes a light source used in an optical coherence tomography apparatus.3. The surface emitting laser according to claim 2 , wherein a Free Spectral Range (FSR) determined depending on an optical distance between the second reflecting mirror and the third reflecting mirror is narrower than a frequency interval expressed by c/4x where x (m) is a predetermined depth image-capturing range in the optical coherence tomography apparatus claim 2 , and c (m/s) is velocity of light.4. The surface emitting laser according to claim 2 , wherein a Free Spectral Range (FSR) determined depending on an optical distance between the second reflecting mirror and the third reflecting mirror is wider than a frequency interval of c/2Ny resulting from dividing a frequency range claim 2 , which is expressed by c/2y where y is a predetermined depth axial image resolution in the optical coherence tomography apparatus and c is velocity of light claim 2 , by a number N of data subjected to ...

OPTICAL SOURCE

An optical source is presented comprising a laser and an optical filter in optical communication with the laser. The laser comprises an optical gain section; and an optical phase control section. The filter is configured to receive light output from the laser and filter the said received light. The source is configured to input the filtered light back into the laser. 138-. (canceled)40. An optical source as claimed in claim 39 , wherein the laser comprises a laser cavity section disposed between a first optical reflector and a second optical reflector claim 39 , the laser cavity section comprising the optical gain section and optical phase control section.4140. An optical source as claimed in claim 39 , wherein:I) at least one of the first or second optical reflectors is a partial optical reflector; and,II) the optical filter is configured to receive laser light from one of the said at least one partial optical reflectors; and,III) the optical source is configured to input filtered light into one of the said at least one partial optical reflectors.42. An optical source as claimed in claim 39 , wherein the optical phase control section is controllable independently from the gain section.45. An optical source as claimed in claim 44 , wherein the third optical reflector is a partial reflector such that it is configured to transmit a portion of the light as an output of the laser source.46. An optical source as claimed in claim 39 , wherein the optical filter comprises a passband filter response.47. An optical source as claimed in claim 46 , wherein filter bandpass full width half maximum width is less than the longitudinal mode spacing of the laser.48. An optical source as claimed in claim 46 , wherein the optical filter comprises an optical thin film filter.49. An optical source as claimed in claim 48 , configured to change the central wavelength of the pass-band response of the optical filter by changing the angle of incidence that the output laser light subtends ...

WAVELENGTH CONTROL SYSTEM FOR PULSE-BY-PULSE WAVELENGTH TARGET TRACKING IN DUV LIGHT SOURCE

Wafer positioning errors in stepper-scanners contribute to imaging defects. Changing the wavelength of the light source's generated light can compensate for wafer positional errors in the Z-direction. The wafer's real-time z-position is determined and a change in wavelength target to offset this error is communicated to the light source. The light source uses this change in wavelength target in a feed-forward operation and, in an embodiment, in combination with existing feedback operations, on a pulse-by-pulse basis for subsequent pulses in a current burst of pulses in addition to receiving the newly-specified laser wavelength target for a subsequent burst of laser pulses. 1. A method of laser wavelength control comprising:(a) receiving, in a laser system controller, a newly-specified laser wavelength target;(b) generating, by the laser system, a burst of laser pulses at the newly-specified laser wavelength target;(c) receiving, in the laser system controller, a change in wavelength target based on a measured wafer positional error;(d) adjusting a prism position in the laser system based on the received change in wavelength target;(e) generating, by the laser system, a next laser pulse of the burst of laser pulses using the adjusted prism position; and,(f) repeating steps (c)-(e) as additional changes in wavelength target are received by the laser system.2. The method of further comprising repeating steps (a) through (f) when another newly-specified laser wavelength target is received.3. The method of wherein the newly-specified wavelength target is received in the laser system every several seconds.4. The method of wherein the changes in wavelength target are received in the laser system approximately every 50 milliseconds.6. The method of wherein adjusting the prism position in the laser system based on a feed-forward operation is also based on a feedback operation.7. A laser system for pulse-by-pulse laser wavelength control comprising:a laser source;a line ...

LASER APPARATUS, MEASUREMENT SYSTEM, AND MEASUREMENT METHOD

A laser apparatus, a measurement apparatus, and a measurement method are provided in which the laser apparatus outputs a frequency-modulated laser beam with a plurality of modes and includes: an optical cavity that has a gain medium for amplifying a light to be input, and an optical SSB modulator for shifting a frequency of the light amplified by the gain medium: and a control part that controls the optical SSB modulator to shift a frequency of a light to be input to the optical SSB modulator. 1. A laser apparatus for outputting a frequency-modulated laser beam with a plurality of modes , the laser apparatus comprising: a gain medium for amplifying a light to be input, and', 'an optical SSB modulator for shifting a frequency of the light amplified by the gain medium; and, 'an optical cavity that has'}control circuitry configured to control the optical SSB modulator to shift a frequency of a light to be input to the optical SSB modulator.2. The laser apparatus according to claim 1 , whereinthe control circuitry is further configured to set a frequency shift amount of the optical SSB modulator.3. The laser apparatus according to claim 2 , wherein a substrate,', 'a main Mach-Zehnder waveguide that is provided on the substrate and has a first arm waveguide and a second arm waveguide,', 'a first sub Mach-Zehnder waveguide provided on the first arm waveguide, and', 'a second sub Mach-Zehnder waveguide provided on the second arm waveguide, and', 'wherein the control circuitry is further configured to supply a DC voltage of a predetermined value and an RF signal to an electrode that is provided on the substrate and corresponds to the main Mach-Zehnder waveguide, the first sub Mach-Zehnder waveguide, and the second sub Mach-Zehnder waveguide, and sets the frequency shift amount by changing a frequency of the RF signal., 'the optical SSB modulator has'}4. The laser apparatus according to claim 1 , wherein the control circuitry is further configured to set a frequency shift ...

BEAM QUALITY CONTROL DEVICE AND LASER DEVICE USING SAME

A beam quality control device includes an optical fiber, a stress-applying portion, and a temperature controller. The optical fiber has a core and a cladding that surrounds an outer peripheral surface of the core. The stress-applying portion is in surface-contact with at least a portion of an outer peripheral surface of the optical fiber. The stress-applying portion has a coefficient of thermal expansion of the stress-applying portion that is different from a coefficient of thermal expansion of the cladding. The temperature controller controls a temperature of the stress-applying portion. The stress-applying portion contracts or expands due to the temperature being changed by the temperature controller such that a distribution of external force applied by the stress-applying portion to the cladding becomes non-uniform in a peripheral direction of the cladding. 1. A beam quality control device , comprising:an optical fiber having a core and a cladding that surrounds an outer peripheral surface of the core;a stress-applying portion that is in surface contact with at least a portion of an outer peripheral surface of the optical fiber and that has a coefficient of thermal expansion of the stress-applying portion that is different from a coefficient of thermal expansion of the cladding; anda temperature controller that controls a temperature of the stress-applying portion,wherein the stress-applying portion contracts or expands due to the temperature being changed by the temperature controller such that a distribution of an external force applied by the stress-applying portion to the cladding becomes non-uniform in a peripheral direction of the cladding.2. The beam quality control device according to claim 1 , further comprising:a heat-conducting plate, is thermally connected to the stress-applying portion and the temperature controller, and conducts heat between the temperature controller and the stress-applying portion, whereinthe stress-applying portion is disposed on ...

Arrayed waveguide grating based hybrid integrated laser having adjustable external cavity

An arrayed waveguide grating based hybrid integrated laser has an adjustable external cavity. The waveguide includes a semiconductor gain die and an optical waveguide chip. The optical waveguide chip includes an arrayed waveguide grating and an arrayed waveguide reflection-controllable component. A resonant cavity is formed by the output end reflection-controllable arrayed waveguide grating chip and the semiconductor gain die. An output wavelength of the laser can be adjusted by changing a driving condition of the reflection-controllable component. The output wavelength is determined by a center wavelength of each channel of the arrayed waveguide grating.

Fast tunable integrated laser

An apparatus includes a wavelength-tunable laser and an electronic controller. The electronic controller is configured to control the wavelength-tunable laser such that an output wavelength of the wavelength-tunable laser performs a zigzag in time. The wavelength-tunable laser is capable of rapidly and densely scanning wavelengths across a broad spectral range.

OPTICAL RESONATOR ARRANGEMENT AND A METHOD FOR ADJUSTING A ROUND-TRIP TIME IN A RESONATOR

In a resonator arrangement () including a resonator () an interferometer () is arranged inside the resonator () and includes at least a first and a second interferometer leg (). The two interferometer legs () have optical path lengths (L L) that differ from each other. According to the invention a splitting ratio is variably adjustable, with which the interferometer () splits radiation () circulating in the resonator () into the first and second interferometer legs (). 112. An optical resonator arrangement () comprising a resonator () , wherein{'b': 9', '9', '9', '2, 'i': a,', 'b, 'an interferometer () having at least a first and a second interferometer leg () is arranged within the resonator (),'}{'b': 9', '1', '9', '2', '1, 'i': a', 'b, 'the first interferometer leg () has a first optical path length (L) and the second interferometer leg () has a second optical path length (L) other than the first optical path length (L), and'}{'b': 9', '8', '2', '9', '9, 'i': a,', 'b, 'a splitting ratio, with which the interferometer () splits radiation () circulating in the resonator () into the first and second interferometer legs (), is variably adjustable.'}2128299a,b. The resonator arrangement according to claim 1 , wherein the resonator arrangement () is configured to change a repetition rate of the resonator () and/or a carrier envelope offset frequency (f) by changing the splitting ratio of the radiation () circulating in the resonator () for the first and second interferometer legs ().311515. The resonator arrangement according to claim 1 , wherein the resonator arrangement () comprises an actuator () for adjusting the splitting ratio claim 1 , wherein the actuator () preferably has a control bandwidth of at least 10 kHz claim 1 , at least 100 kHz or at least 1000 kHz.41111522. The resonator arrangement according to claim 3 , wherein the resonator arrangement () comprises a measurement apparatus () configured to measure a shift of the resonant lines obtained by the ...

VARIABLE-WAVELENGTH LIGHT SOURCE

A variable-wavelength light source is provided with a first laser medium, a first optical resonator constituted of a total reflection mirror and a half-mirror, a second laser medium, a second optical resonator constituted of a total reflection mirror and the half-mirror, a first filter having a pair of first mirrors configured to cause first light and second light to be transmitted and reflected selectively, a second filter having a pair of second mirrors configured to cause the first light and the second light to be transmitted and reflected selectively, a first drive mechanism configured to operate the first mirror and the second mirror in conjunction with each other, and a second drive mechanism configured to operate the second mirror. 1: A variable-wavelength light source comprising:a first laser medium configured to amplify first light having a first wavelength band;a first total reflection mirror and a first partial reflection mirror constituting a first optical resonator configured to cause the first light to optically resonate;a second laser medium configured to amplify second light having a second wavelength band;a second total reflection mirror and a second partial reflection mirror constituting a second optical resonator configured to cause the second light to optically resonate;a first Fabry-Perot interference filter having a pair of first mirrors, arranged at a first position which is a position between the first laser medium and the first partial reflection mirror on a first optical path of the first light and is a position between the second laser medium and the second partial reflection mirror on a second optical path of the second light, and configured to cause the first light and the second light to be transmitted and reflected selectively;a second Fabry-Perot interference filter having a pair of second mirrors, arranged at a second position which is a position between the first laser medium and the first Fabry-Perot interference filter on the ...

FULLY CONTROLLABLE BURST SHAPING INDIVIDUAL PULSES FROM PICOSECOND FIBER LASERS

A pulse shaper includes a seed laser situated to emit laser pulses, an amplitude modulator situated to receive one or more laser pulse bursts from the seed laser, and a pulse signal generator situated to send a seed pulse signal with a predetermined delay to the seed laser so that the seed laser emits the laser pulses in one or more laser pulse bursts at a selected frequency with each laser pulse burst having a selected number of laser pulses and a selected temporal spacing between laser pulses in the laser pulse burst and situated to send an amplitude pulse signal so that the amplitude modulator adjusts the amplitude of at least one laser pulse in each laser pulse burst. 1. An apparatus , comprising:a seed laser;an amplitude modulator situated to receive one or more laser pulse bursts from the seed laser; anda pulse signal generator situated to couple a seed pulse signal with a predetermined delay to the seed laser so that the seed laser emits laser pulses in the one or more laser pulse bursts at a selected frequency, each laser pulse burst having a selected number of laser pulses and a selected temporal spacing between laser pulses, and to couple a pulse amplitude signal to the amplitude modulator so that the amplitude modulator adjusts the amplitude of at least one laser pulse in each of the one or more laser pulse bursts.2. The apparatus of claim 1 , wherein the pulse signal generator includes a clock burst generator situated to generate a clock burst associated with the seed pulse signal.3. The apparatus of claim 2 , wherein the clock burst generator includes a phase locked loop operable to generate a clock burst frequency by phase-locking a voltage controlled oscillator signal to a reference signal.4. The apparatus of claim 3 , wherein the reference signal is supplied by an internal clock of the pulse signal generator.5. The apparatus of claim 2 , wherein the pulse signal generator includes a programmable delay operable to provide the predetermined delay to ...

LOW CARRIER PHASE NOISE FIBER OSCILLATORS

The present disclosure relates to the design of fiber frequency comb lasers with low carrier phase noise. Examples of these low carrier phase noise oscillators can be constructed from both soliton and dispersion compensated fiber lasers via the use of intra-cavity amplitude modulators such as graphene modulators. In low carrier phase noise dispersion compensated fiber frequency comb lasers, graphene and/or bulk modulators can further be used, for example, for phase locking of one comb line to an external continuous wave (cw) reference laser via high bandwidth control of the repetition rate of the comb laser via the graphene modulator. As a result a low phase noise radio frequency (RF) signal can be generated. In some implementations, a frequency comb exhibiting phase noise suppression of at least about 10 dB over a frequency range up to about 100 kHz is provided. 1) A fiber frequency comb system having a free-running carrier envelope offset frequency with a 3 dB linewidth Δfless than 1 MHz , said fiber frequency comb system further comprising:{'sub': opt', 'opt', 'ceo, 'an intra-cavity amplitude modulator, said intra-cavity amplitude modulator configured for repetition rate control of said fiber frequency comb system, wherein said intra-cavity amplitude modulator is configured to allow for a frequency modulation range Δfof a comb line in an optical frequency domain, said frequency modulation range being achievable at least at one modulation frequency greater than 20 kHz, wherein Δfis greater than Δf/100.'}2) A fiber frequency comb system according to claim 1 , further comprising:a continuous wave (cw) reference laser;{'sub': 'b', 'said fiber frequency comb system further configured to generate a beat signal fbetween said cw reference laser and at least one comb line of said fiber frequency comb system;'}said intra-cavity amplitude modulator configured for high precision phase locking of said comb line to said cw reference laser.3) A fiber frequency comb system ...

External Cavity Tunable Laser And Cavity Mode Locking Method Thereof

The present invention relates to an external cavity tunable laser and a cavity mode locking method thereof. In an embodiment, an external cavity tunable laser comprises a semiconductor amplifier having a partial reflective film provided on one end and an anti-reflective film provided on the other end, a cavity mirror provided at the anti-reflective end to define an external cavity therebetween, a large-range phasing assembly and a quick phasing assembly provided to adjust the optical length of the external cavity independently, an optical power detector provided to detect the optical power of the light output from the semiconductor amplifier, and a control unit in communication with the optical power detector, the large-range phasing assembly, and the quick phasing assembly. 1. An external cavity tunable laser comprising:a semiconductor amplifier having a partial reflective film provided on one end and an anti-reflective film provided on the other end;a cavity mirror provided at the anti-reflective end of the semiconductor amplifier to define an external cavity therebetween;a large-range phasing assembly and a quick phasing assembly provided to adjust the optical length of the external cavity independently;an optical power detector provided at the partial reflective end of the semiconductor amplifier to detect the optical power of the light output from the semiconductor amplifier; and [{'b': '1', 'sub': 'Max', 'monitoring whether a difference between the output optical power value received from the optical power detector and a previous maximum output optical power value (P) in a cavity mode locking state is higher than a threshold;'}, {'sub': f', 'Max, 'b': '2', 'if yes, changing the driving input (D) of the quick phasing assembly to obtain a present maximum output optical power value (P);'}, {'sub': f', 'f', 'L, 'converting the driving input change (D−CD) of the quick phasing assembly to a driving input change (ΔD) of the large-range phasing assembly; and'}, ' ...

AMPLITUDE-MODULATED LASER

Systems and methods are described for producing an amplitude-modulated laser pulse train. The laser pulse train can be used to cause fluorescence in materials at which the pulse trains are directed. The parameters of the laser pulse train are selected to increase fluorescence relative to a constant-amplitude laser pulse train. The amplitude-modulated laser pulse trains produced using the teachings of this invention can be used to enable detection of specific molecules in applications such as gene or protein sequencing. 1. A mode-locked laser comprising:at least one laser diode; andat least one laser cavity containing at least one gain medium;wherein the output of the laser is configured to produce a train of laser pulses having a modulated amplitude.2. The mode-locked laser of claim 1 , wherein the amplitude of the laser pulses in the laser pulse train modulates substantially periodically claim 1 , resulting in a periodically modulated laser pulse train.3. The mode-locked laser of claim 2 ,wherein one or more parameters of the periodically modulated laser pulse train are selected to achieve either or both of:improvement in a fluorescence yield of one or more dyes to which the laser pulse train is applied; orimprovement of the saturation characteristics of the dye, thereby increasing the longevity of the dye and reducing the generation of host species such as free radicals that can affect target molecules;wherein the one or more parameters include peak amplitude, modulation shape, repetition rate of pulses in the laser pulse train, laser wavelength, photon energy in the light emitted by the laser, pulse duty cycle, pulse width, and modulation duty cycle.4. The mode-locked laser of claim 3 , wherein the modulation shape is chosen from a set of shapes including a square claim 3 , triangle claim 3 , sinusoid claim 3 , and an arbitrary shape with varying pulse rise times claim 3 , pulse fall times claim 3 , and pulse duty cycles.5. The mode-locked laser of claim 1 , ...

Tunable soi laser

A wavelength tunable silicon-on-insulator (SOI) laser comprising: a laser cavity including: a semiconductor gain medium having a front end and a back end, wherein a mirror of the laser cavity is located at the back end of the semiconductor gain medium; and a phase-tunable waveguide platform coupled to the front end of the semiconductor gain medium, the phase-tunable waveguide platform comprising: a first resonator and a second resonator; at least one resonator being a phase-tunable resonator; wherein the first resonator is any one of: an MMI device including a pair of reflective surfaces defining a resonator cavity therebetween such that the device is configured to act as a Fabry-Perot filter; a ring resonator; or a waveguide Fabry-Perot filter; and wherein the second resonator is any one of: an MMI device including a pair of reflective surfaces defining a resonator cavity therebetween such that the device is configured to act as a Fabry-Perot filter; a ring resonator; or a waveguide Fabry-Perot filter.

Ultrashort Pulse Fiber Laser

The invention is a passively mode-locked ultrashort pulse fiber laser for generating ultrashort laser pulses, including a resonator in a figure-of-eight configuration, wherein the resonator has a main ring and a secondary ring optically coupled thereto designed as a non-linear Sagnac interferometer, and wherein the main ring and the secondary ring are constructed of polarization-maintaining optical fibers, and the main ring and/or secondary ring have a fiber section designed as a laser-active medium, wherein the laser-active medium is optically pumped through an externally-coupled pump light source which is also comprised, wherein the ultrashort pulse fiber laser is developed in that a separate optical unit is provided in the resonator as a dispersion compensation unit for compensating a group delay dispersion of the ultrashort laser pulses.

WAVELENGTH TUNABLE OPTICAL TRANSMITTER

An optical transmitter includes: a wavelength tunable light source; an etalon filter that filters output light of the light source; a measurement unit that generates a monitor value corresponding to power of output light of the etalon filter; and a controller that controls a temperature of the light source and a temperature of the etalon filter. Until the wavelength of the output light of the light source is adjusted to a target wavelength, the controller alternately performs first processing to control the temperature of the light source based on the monitor value so as to shift the wavelength of the output light of the light source by a specified amount, and second processing to control the temperature of the etalon filter based on the monitor value so as to shift the transmission characteristics of the etalon filter by the specified amount. 1. An optical transmitter comprising:a wavelength tunable light source;an etalon filter that filters output light of the wavelength tunable light source;a measurement unit that generates a monitor value corresponding to power of output light of the etalon filter; anda controller that controls a temperature of the wavelength tunable light source to adjust a wavelength of the output light of the wavelength tunable light source, and controls a temperature of the etalon filter to adjust transmission characteristics of the etalon filter, whereinthe controller controls the temperature of the wavelength tunable light source to adjust the wavelength of the output light of the wavelength tunable light source to a specified wavelength, andduring the wavelength of the output light of the wavelength tunable light source is adjusted from the specified wavelength to a target wavelength, the controller alternately performs first processing to control the temperature of the wavelength tunable light source based on the monitor value so as to shift the wavelength of the output light of the wavelength tunable light source by a specified amount, ...

Tunable Laser with a Cascaded Filter and Comb Reflector

A laser comprises a gain medium, and a mirror coupled to the gain medium and comprising a coupler coupled to the gain medium, a phase section coupled to the coupler, a bandpass filter coupled to the phase section, and a comb reflector (CR) coupled to the bandpass filter. A laser chip package comprises a substrate, and a laser coupled to the substrate and comprising a filter comprising a first interferometer with a first transmittance, and a second interferometer with a second transmittance, wherein the filter is configured to provide a filter transmittance based on the first transmittance and the second transmittance, and a comb reflector (CR) coupled to the filter and comprising a ring with a circumference, and a refractive index, wherein the CR is configured to provide a CR reflectivity based on the circumference and the refractive index. 1. A laser comprising:a gain medium; and a coupler coupled to the gain medium;', 'a phase section coupled to the coupler;', 'a bandpass filter coupled to the phase section; and', 'a comb reflector (CR) coupled to the bandpass filter., 'a mirror coupled to the gain medium and comprising2. The laser of claim 1 , wherein the bandpass filter comprises:a first Mach-Zehnder interferometer (MZI); anda second MZI coupled to the first MZI and the CR.3. The laser of claim 2 , wherein the first MZI comprises:a first splitter;a first local heater coupled to the first splitter; anda second splitter coupled to the first splitter and the first local heater.4. The laser of claim 3 , wherein the second MZI comprises:a third splitter coupled to the second splitter;a second local heater coupled to the third splitter; anda fourth splitter coupled to the third splitter and the second local heater.5. The laser of claim 1 , wherein the CR comprises:a first splitter coupled to the bandpass filter; and a second splitter coupled to the first splitter;', 'a local heater coupled to the second splitter; and', 'a third splitter coupled to the local heater and ...

ACOUSTO-OPTIC SYSTEM HAVING PHASE-SHIFTING REFLECTOR

A beam positioner can be broadly characterized as including a first acousto-optic (AO) deflector (AOD) operative to diffract an incident beam of linearly polarized laser light, wherein the first AOD has a first diffraction axis and wherein the first AOD is oriented such that the first diffraction axis has a predetermined spatial relationship with the plane of polarization of the linearly polarized laser light. The beam positioner can include at least one phase-shifting reflector arranged within a beam path along which light is propagatable from the first AOD. The at least one phase-shifting reflector can be configured and oriented to rotate the plane of polarization of light diffracted by the first AOD. 1. A beam positioner , comprising:a first acousto-optic (AO) deflector (AOD) operative to diffract an incident beam of linearly polarized laser light, wherein the first AOD has a first diffraction axis and wherein the first AOD is oriented such that the first diffraction axis has a predetermined spatial relationship with the plane of polarization of the linearly polarized laser light; andat least one phase-shifting reflector arranged within a beam path along which light is propagatable from the first AOD, wherein the at least one phase-shifting reflector is configured and oriented to rotate the plane of polarization of light diffracted by the first AOD.2. The beam positioner of claim 1 , further comprising a second AOD arranged within the beam path and operative to diffract an incident beam of linearly polarized laser light claim 1 , wherein the second AOD has a second diffraction axis claim 1 , wherein the at least one phase-shifting reflector is arranged between the first AOD and the second AOD.3. The beam positioner of claim 2 , wherein the first diffraction axis is parallel to the second diffraction axis.4. The beam positioner of claim 2 , wherein the first diffraction axis is perpendicular to the second diffraction axis.5. The beam positioner of claim 1 , ...

Narrowband Pump module for Diode Pumped Alkali Vapors

A narrow-band diode pumped alkali laser (DPAL) comprising a diode emitter assembly of broad area diode lasers arranged in a stack or array to emit longitudinally at a power level in a power range of 10-1500 W through a frequency selective element assembly aligned and positioned in an external laser cavity to the diode emitter assembly. The frequency selective element assembly comprising: an optical cell containing alkali vapor positioned between a pair of crossed polarizers; a partially reflective mirror that reflects a portion of light passing through the optical cell back toward the diode emitter assembly; and magnetic field producing components that produce a magnetic field through the optical cell that creates a 90° polarization of light passing through the optical cell at a narrow-band frequency corresponding to the absorption line of alkali atom, attenuating components of the light passing through the optical cell at frequencies outside of the narrow-band frequency. 1. A narrow-band diode pump module:a diode emitter assembly comprising a plurality of broad area diode lasers arranged in a selected one of: (i) a stack; and (ii) an array to emit at a power level in a power range of 10¬1500 W; and a pair of crossed polarizers;', 'an optical cell containing alkali vapor positioned between the pair of crossed polarizers;', 'a partially reflective mirror that reflects a portion of light passing through the optical cell back toward the pump module; and', 'magnetic field producing components that produce a magnetic field through the optical cell that creates a 90° rotation of the polarization of light passing through the optical cell at a selected narrow-band frequency corresponding to the absorption line of alkali atom, attenuating components of the light passing through the optical cell at frequencies outside of the narrow-band frequency., 'a frequency selective element assembly aligned and positioned in an external laser cavity to the pump module, the frequency ...

Method and generator for generating ultra-short light pulses

This invention relates to the field of laser technology and more particularly to the ultra-short pulse generation methods and generators. One round trip of the ultra-short light pulse formation inside a generator optical loop comprises these steps: amplification of the light pulse, spectral broadening of the amplified light pulse due to the optical Kerr effect inside the optically transparent medium, selection of the predeterminated spectral components of the spectrally broadened light pulses by using the first spectrally-sensitive optical element, then again follows amplification of the selected light pulses, spectral broadening of the amplified light pulse due to the optical Kerr effect inside the optically transparent medium and selection of the predeterminated spectral components of the spectrally broadened light pulses by using the second spectrally-sensitive optical element, where spectral components of the light pulses selected using the first spectrally-sensitive optical element are different than the spectral components of the light pulses selected using the second spectrally-sensitive optical element.

Optical Lasing Device and Method for Generating a Lasing Mode in Such Device

An optical lasing device includes a gain medium arranged in a lasing cavity having an optical axis, the gain medium providing light amplification; a periodic grid generator filter arranged in the lasing cavity; a channel selector arranged in the lasing cavity and configured to select a lasing mode of the amplified light corresponding to a frequency channel defined by the periodic grid generator filter according to an optimization criterion; and a band-pass filter arranged in the lasing cavity and configured to suppress lasing modes which are outside of a pass-band of the band-pass filter. 1. An optical lasing device comprising:a gain medium arranged in a lasing cavity having an optical axis, wherein the gain medium provides light amplification;a periodic grid generator filter arranged in the lasing cavity;a channel selector arranged in the lasing cavity and configured to select a lasing mode of the amplified light corresponding to a frequency channel defined by the periodic grid generator filter according to an optimization criterion; anda band-pass filter arranged in the lasing cavity and configured to suppress lasing modes which are outside of a pass-band of the band-pass filter.2. The optical lasing device of claim 1 , wherein the optimization criterion comprises tuning the channel selector within a frequency channel range such that a single lasing mode arises at a frequency corresponding to one channel of the periodic grid generator filter.3. The optical lasing device of claim 1 , wherein the pass-band of the band-pass filter is configured to coincide with a channels range according to a specification claim 1 , wherein the specification comprises a C-band or L-band according to International Telecommunication Union (ITU) specification.4. The optical lasing device of claim 1 , wherein the channel selector comprises a Guided Mode Resonance tunable mirror.5. The optical lasing device of claim 4 , wherein the Guided Mode Resonance tunable mirror comprises at least ...

DEVICE, METHOD, AND SYSTEM FOR IMAGING LASER AMPLIFIER

An optical image amplifier device capable of amplifying low-intensity backscattered illumination includes an optical port having an input, an output, and a controller having an ON state and an OFF state, the controller connecting the input and the output to form an optical loop in the ON state and disconnecting the input and the output in the OFF state, and an optical relay housing the optical loop and connected to the optical port having a gain medium configured for amplifying a signal beam propagating inside the optical loop in the ON state. 1. An optical image amplifier device , comprising:an optical relay housing an optical loop and having a gain medium; andan optical port connected to the optical relay and having an input that includes input optics for inputting a signal beam into the optical relay, an output that includes output optics for outputting the signal beam after being amplified, and a controller having an ON state and an OFF state, the controller connecting the input and the output to form the optical loop in the ON state and disconnecting the input and the output in the OFF state, the gain medium being configured to amplify the signal beam propagating inside the optical loop when the controller is in the ON state.2. The amplifier device of wherein the controller is positioned between a first polarizer and a second polarizer claim 1 , the controller further comprising:a half-wave plate and an electronically controlled wave plate.3. (canceled)4. The amplifier device of wherein the optical relay further comprises a plurality of image formation optics.5. The amplifier device of wherein the first polarizer is positioned adjacent to a first side of the electronically controlled wave plate and configured to reflect the signal beam when the electronically controlled wave plate is in the ON state.6. The amplifier device of wherein the second polarizer is positioned adjacent to a second side of the electronically controlled wave plate and configured to ...

RING RESONATOR AND MANUFACTURING METHOD THEREOF

A ring resonator includes a core. Both ends of the core in a lengthwise direction are connected to have a circular shape. The ring resonator further includes a cladding surrounding the core, a jacket surrounding the cladding and a sleeve surrounding a portion of the jacket. A portion of the core is exposed from the cladding and the jacket. 1. A ring resonator , comprising:a core having two ends, wherein both ends of the core in a lengthwise direction are connected to have a circular shape;a cladding surrounding the core; anda jacket surrounding the cladding,wherein a portion of the core is exposed from the cladding and the jacket.2. The ring resonator of claim 1 , further comprising:a sleeve surrounding a portion of the jacket.3. The ring resonator of claim 1 , further comprising:a shrinking sleeve that is arranged to surround a portion where the both ends of the core are connected to each other.4. The ring resonator of claim 3 , wherein the shrinking sleeve is fitted to the jacket.5. A method of manufacturing a ring resonator claim 3 , comprising:removing portions of a jacket which are arranged on both ends and a central portion of an optical fiber, wherein the optical fiber includes a core having a predetermined length, a cladding surrounding the core, and the jacket surrounding the cladding;connecting both ends of the optical fiber; andetching the cladding arranged in the central portion of the optical fiber from which the portion of the jacket is removed.6. The method of claim 5 , further comprising:inserting a sleeve to surround a remaining portion of the jacket, before the connecting of both ends of the optical fiber.7. The method of further comprising:providing a shrinking sleeve to surround a portion where both ends of the optical fiber are connected.8. The method of claim 5 , wherein the etching of the cladding includes etching the cladding using an aqueous solution of hydrofluoric acid.9. The method of claim 8 , wherein the aqueous solution of hydrofluoric ...

Fiber-based saturable absorber

Methods, apparatus, and systems for active saturable absorbance of an optical beam. An active saturable absorber may comprise an optical input to receive an optical beam, and one or more lengths of fiber between the optical input and an optical output. At least one of the lengths of fiber comprises a confinement region that is optically coupled to the output. The active saturable absorber may further comprise an optical detector to sense a characteristic of the optical beam, such as power. The active saturable absorber may further comprise a perturbation device to modulate, through action upon the one or more lengths of fiber, a transmittance of the beam through a fiber confinement region from a lower transmittance level to a higher transmittance level based on an indication of the characteristic sensed while the transmittance level is low.

EXTERNAL OPTICAL FEEDBACK ELEMENT FOR TUNING A MULTI-WAVELENGTH GAS LASER

An external optical feedback element () for tuning an output beam of a gas laser () having multiple wavelengths includes a partially reflective optical element () positioned on a beam path of the output beam () outside of an internal optical cavity of the gas laser (), and a stage () to support the optical element and adjust rotation, horizontal tilt angle, and vertical tilt angle of the optical element with respect to the beam path. The output beam () is partially reflected at the optical element () and fed back into the internal optical cavity of the gas laser (), with the intensity varying for multiple wavelengths and adjusted by changing rotation, horizontal tilt angle and vertical tilt angle of the optical element. Thereby, a variable feedback of the output beam into the internal optical cavity of the gas laser is provided, which leads to a selective output wavelength of the gas laser, either at a single line or at multiple lines simultaneously. This setup may allow to control the wavelength of a commercial CO2 gas laser without a modification of the laser itself by adding a coupled cavity with a wavelength selective element like a grating to the given gas laser resonator. 1. An external optical feedback element for tuning an output beam of a gas laser having a plurality of wavelengths , comprising:a partially reflecting optical element positioned on a beam path of the output beam outside of an internal optical cavity of the gas laser; anda stage to support the optical element and adjust a rotation, a horizontal tilt angle, and a vertical tilt angle of the optical element with respect to the beam path of the output beam; the intensity of the reflected beam varies for the plurality of wavelengths,', 'the intensity of the reflected beam for each of the plurality of wavelengths is adjusted by changing the rotation, the horizontal tilt angle, and the vertical tilt angle of the optical element, and', 'thereby a wavelength is selected at which the output beam is fed ...

TUNABLE LASER

Examples of the present disclosure include a tunable laser comprising a waveguide including gain section. The waveguide overlies and is optically coupled to another waveguide. The another waveguide has a reflector at one end. A laser cavity is formed in the waveguides. 1. (canceled)2. (canceled)3. (canceled)4. (canceled)5. (canceled)6. (canceled)7. (canceled)8. (canceled)9. (canceled)10. (canceled)11. (canceled)12. (canceled)13. A tunable laser comprising:a first waveguide comprising a first III-V semiconductor material and including a first gain section;a second waveguide comprising a second III-V semiconductor material and including a second gain section;an optical coupler to couple light between the first waveguide and the second waveguide;wherein the first waveguide overlies and is optically coupled to a third waveguide, the third waveguide comprising alternating layers of third and fifth III-V semiconductor materials, said third III-V semiconductor material having a refractive index which is higher than a refractive index of the fifth III-V semiconductor material;wherein the second waveguide overlies and is optically coupled to a fourth waveguide which comprises alternating layers of fourth and sixth III-V semiconductor materials, wherein the fourth III-V semiconductor material has a refractive index which is higher than a refractive index of the sixth III-V semiconductor material; andwherein a first laser cavity is formed between the optical coupler and a reflector of the third waveguide and a second laser cavity is formed between the optical coupler and a reflector of the fourth waveguide.14. The tunable laser of wherein the first laser cavity has a free spectral range (FSR) which is different to a FSR of the second laser cavity and wherein a resonance wavelength of at least one of the first laser cavity and the second laser cavity is tunable to provide wavelength tuning of the tunable laser via the Vernier effect.15. The tunable laser of wherein the first ...

Acousto-Optic Tuning of Lasers

A semiconductor laser tuned with an acousto-optic modulator. The acousto-optic modulator may generate standing waves or traveling waves. When traveling waves are used, a second acousto-optic modulator may be used in a reverse orientation to cancel out a chirp created in the first acousto-optic modulator. The acousto-optic modulator may be used with standing-wave laser resonators or ring lasers. 1. An infrared laser , comprising:a. a quantum cascade laser gain medium having a first end and a second end;b. a first collimating lens adjacent to the first end of the gain medium and receiving a first undiffracted beam from the gain medium defining a first path;c. an anti-reflection coating at the first end of the gain medium, the anti-reflection coating facing the first collimating lens;d. a second collimating lens adjacent to the second end of the gain medium and receiving a second output beam from the gain medium;e. a partially reflective coating at the second end of the gain medium, the partially reflective coating facing the second collimating lens;f. a first acousto-optic modulator adjacent to the first collimating lens and opposite the gain medium and fixed in place, the first acousto-optic modulator having a first radiofrequency and receiving the first undiffracted beam and subsequently emitting a diffracted beam;g. a second acousto-optic modulator through which the diffracted beam passes, the second acousto-optic modulator having a second radiofrequency; andh. a first highly reflective mirror positioned to receive the diffracted beam from the second acousto-optic modulator, and reflect the diffracted beam back to the second acousto-optic modulator to the first acousto-optic modulator and back to the gain medium to amplify a wavelength tuned beam, wherein the first and second acousto-optic modulator radiofrequencies are electronically controlled to produce the diffracted beam at a desired optical wavelength, (i) a first transparent material having a first end and a ...