Способ автоматического измерения и управления длиной волны перестраиваемого источника оптического излучения и устройство для его осуществления

Изобретение относится к области оптического приборостроения и касается способа автоматического измерения и управления длиной волны перестраиваемого источника оптического излучения. Излучение перестраиваемого источника излучения направляют в оптическое волокно и делят на ветвь выходного излучения и измерительную ветвь, идущую во второй волоконно-оптический разветвитель, в котором делят излучение на первый и второй оптические пути. В первом оптическом пути выполняют линейное изменение интенсивности оптического излучения во время перестройки частоты излучения посредством спектрального оптического фильтра, коэффициент пропускания которого линейным образом зависит от частоты излучения. Одновременно измеряют интенсивности оптического излучения первого оптического пути и второго оптического пути, выполняют фильтрацию и нормировку электрического сигнала и формируют калибровочную кривую посредством разового одновременного измерения длины волны перестраиваемого источника оптического излучения и амплитуды ...

Reduction of the noise from laser transmitters

In the case of laser transmitters, the laser noise can increase as a result of reflection to such an extent that the transmission is interfered with, particularly at high bit rates and with wide bandwidths. The invention proposes that the laser noise be minimised by setting a specific separation between the laser diode and the input optics or fibre ends, the minimising being achieved by means of a temperature change of the laser module. This is enabled in a simple manner by an actuating signal which is dependent on the laser noise being produced and by this signal being passed to the temperature regulator of the Peltier cooler contained in the laser module.

Unterseitenemittierender Oberflächenemissionslaser mit Vertikalresonator (VCSEL)

Ein unterseitenemittierender Oberflächenemissionslaser mit Vertikalresonator, bei dem das emittierte Licht ohne Behinderung überwacht werden kann. Es sind keine zusätzlichen Befestigungen, wie beispielsweise ein Sockel, erforderlich, um eine Ausgabe zu beobachten, wobei in herkömmlichen Anordnungen Befestigungen erforderlich sind.

VERFAHREN ZUR REGELUNG DER AUSGANGSLEISTUNG EINES HALBLEITERLASERS

Steuerungsvorrichtung für Halbleiterlaser zur Stabilisierung der optischen Ausstrahlung desselben

MIT EINEM FIBERENDE VERSEHENER OPTOELEKTRONISCHER WANDLER.

Optischer Zwischenverstärker.

KOMMUNIKATIONSMODUL MIT PARALLELEN SENDEDIODEN

Laser mit externem Resonator und verbessertem Einzelmodenbetrieb

Treiberstufe für Halbleiterlaser

SPEKTROSKOPISCHES KATHETERSYSTEM MIT BREIT ABSTIMMBARER QUELLE

Laserdiodenstabilisator für ein optoelektronisches Transceiver-Modul und Verfahren zur Steuerung der Vorspannung

Optoelektronisches Bauelement und Verfahren zu dessen Herstellung

Halbleiterlaservorrichtung und optoelektronisches Strahlumlenkelement für eine Halbleiterlaservorrichtung

Es wird eine Halbleiterlaservorrichtung (100) angegeben mit einer kantenemittierenden Halbleiterlaserdiode (1), die im Betrieb Laserlicht (10) entlang einer horizontalen Richtung (91) abstrahlt, einem Reflektorelement (29), das einen ersten Teil (11) des Laserlichts in eine vertikale Richtung (92) umlenkt, während sich ein zweiter Teil (12) des Laserlichts in horizontaler Richtung weiter ausbreitet, und einem Detektorelement (3), das zumindest teilweise in einem Strahlengang des zweiten Teils des Laserlichts angeordnet ist.Weiterhin wird ein optoelektronisches Strahlumlenkelement (7) für eine Halbleiterlaservorrichtung (100) angegeben.

Lichtquelleneinheit variabler Wellenlänge

Eine Lichtquelleneinheit variabler Wellenlänge zum Senden von Ausgangslicht einer beliebigen Wellenlänge, ausgewählt in einem Lichtquellenabschnitt variabler Wellenlänge, umfasst einen optischen variablen Abschwächer, welcher außerhalb des Lichtquellenabschnitts variabler Wellenlänge angeordnet ist, und eine Steuerschaltung zum Steuern des Abschwächungsbetrags des optischen variablen Abschwächers in Reaktion auf Licht, geliefert durch Teilen eines Teils des Ausgangslichts.

Optical amplification control apparatus, method for controlling semiconductor optical amplifier, and optical transmission equipment

Laser systems

LASER DIODE INTENSITY AND WAVELENGTH CONTROL

An optical transmitter

The transmitter comprises a laser diode 1, having front 1a and back 1b emission facets, mounted in a location recess 2 of an optical chip. The recess 2 has an inclined reflective facet 2c at one end, an waveguide 4 adjacent the other end and support surfaces 8a, 8b on which the laser is supported and which determines the location of the laser. The reflective facet is arranged to receive light directly from the back emission facet and to reflect the light out of the plane of the chip to a monitoring photodiode 7. A method of forming the location recess is also described. The optical axis of the laser diode is preferably inclined by a few degrees to the optical axis of the waveguide to reduce the interference caused by reflections.

Control and calibration of laser systems

Optical source with monitor

Optoelectronic transceiver module laser diode stabilizer and bias control method

FREQUENCY REFERENCING SYSTEM

APPARATUS FOR MEASURING REFLECTIVITIES OF RESONATOR FACETS OF SEMICONDUCTOR LASER

Optimisation of the laser operating point in a laser absorption spectrometer

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

Optical beam splitter and method for performing optical beam splitting

DRIVING CIRCUIT FOR LASER DIODE

FIBRE TAILED OPTO ELECTRONIC TRANSDUCER

OPTICAL RADIATION GENERATOR ELECTRICALLY CONTROLLED

... 1506750 Optical generator with feedback THOMSON-CSF 4 July 1975 [5 July 1974] 28376/75 Heading G1A Such a generator controlled by a current has two terminals 3, 10 for this current connected to current amplifier A, with its output connected to L.E.D. L with a radiating surface close to and optically coupled by a transparent medium M to an end of an optical fibre F and to photodiode P connected to the input of amplifier A 2 , with its output connected to the input of A 1 . GaAs L.E.D. L and photodiode P which is a junction on a silicon substrate, are attached by electrically conductive weld layers to conducting substrate S. In the embodiment of Fig. 2 (not shown) the amplifiers are outside the substrate S. In that of Fig. 3 the amplifiers A 1 A 2 and photodiode P, are an integrated circuit on a silicon base. In the embodiment of Fig. 4 (not shown), the diode P and fibre F face opposite polished ends of laser diode (L 1 ).

LASER SYSTEM WITH EXTERNAL OPTICAL FEEDBACK AND USE OF SUCH A SYSTEM IN THE GRAPHICS INDUSTRY

Drive circuit for a laser diode

The invention relates to a drive circuit for a laser diode, which can be used as a miniature laser for therapeutic purposes. The laser diode LD is in this case operated via an electronic control circuit, which is controlled via a photodiode PD. In order to protect the laser diode LD from overcurrent spikes when switching on and off by means of a pushbutton T or if this pushbutton bounces, the protective resistance for the laser diode LD, which is formed by the resistors R3 and R4, is at least partially provided by the resistance of a low-pass filter on the input side, whose capacitor is formed by the capacitor C1. In addition, a transistor T3 is provided, which monitors the collector/emitter voltage of the control transistor T2 of the laser diode LD so that the current through the laser diode LD is dynamically limited. ...

ANSTEUERSCHALTUNG FÜR EINE LASERDIODE

MINIATURLASER FÜR HUMAN- UND VETERINÄRMEDIZINISCHE ANWENDUNG

INTERFEROMETRISCHE EINRICHTUNG ZUR MESSUNG DER LAGE EINES REFLEKTIERENDEN OBJEKTES

MINIATURE LASER FOR HUMANUND VETERINARY APPLICATION

ACHIEVEMENT-CONTROLLED WELLENLÄNGESTABILISATIONSSYSTEM

INTERFEROMETRISCHE EINRICHTUNG ZUR MESSUNG DER LAGE EINES REFLEKTIERENDEN OBJEKTES

SURFACE-EMITTING LASER APPARATUS WITH EXTERNAL RESONATOR

OPTO-ELECTRONIC TRANSMISSION DEVICE

MINIATURE LASER FOR HUMAN AND VETERINARY APPLICATION.

DIODE LASER DEVICE FOR OPTICAL HEAD.

REGULAR OPTICAL AMPLIFIER

DRIVER CIRCUIT FOR LASER DIODES

MONOLITHICALLY INTEGRATED CIRCUIT FOR REGULATING THE LIGHT ACHIEVEMENT OF A LASER DIODE

STABILITY FACTORS FOR TUNABLE DIODE LASERS WITH SEVERAL SECTIONS

SEMICONDUCTOR LASER FOR OPTICAL HEAD

Wavelength control of an external-cavity tuneable laser

Laser optics integrated control system and method of operation

Transmitter photonic integrated circuit

Optical amplifier circuit

Coupled cavity laser source for telecommunications

Automatic compensation of cnr and omi in a laser transmitter

Tunable laser with microactuator

DIGITAL OPTICAL NETWORK ARCHITECTURE

A digital optical network (DON) is a new approach to low-cost, more compact optical transmitter modules and optical receiver modules for deployment in optical transport networks (OTNs). One important aspect of a digital optical network is the incorporation in these modules of transmitter photonic integrated circuit (TxPIC) chips and receiver photonic integrated circuit (TxPIC) chips in lieu of discrete modulated sources and detector sources with discrete multiplexers or demultiplexers.

OUTPUT POWER MONITORING IN AN OPTICAL PREAMPLIFIER

Tapless output power monitoring is used when amplifying and converting an optical signal to an electrical signal, e.g., in a communications receiver of an optical transmission system. An optical preamplifier amplifies an intensity-modulated optical input signal to produce an amplified intensity-modulated optical signal. An optical-to- electrical (O-E) converter demodulates and converts the amplified intensity- modulated optical signal into an electrical output signal. A current monitor monitors a DC bias current of the optical-to-electrical (O-E) converter and produces a feedback signal proportional to the DC bias current. The optical preamplifier adjusts the gain of the amplified optical signal based on the feedback signal.

LASER MODULATORS

An optical transmitter module comprises a single package (21) enclosing a laser assembly (22, 23, 24) and an integrated optical circuit (32) having an input waveguide and an output waveguide. An optical fibre stub (27) optically interconnects the laser assembly and the optical circuit (32), the fibre stub (27) having one end supported to receive light from the laser assembly and the other end (33) optically coupled to the input waveguide of the optical circuit. An output optical fibre (34) is in optical communication with the output waveguide of the optical circuit and leads out of the package, whereby light emanating from the laser assembly is fed to the optical circuit and is there subjected to data-encoding before leaving the package through the output optical fibre.

TRANSMITTER PHOTONIC INTEGRATED CIRCUIT (TXPIC) CHIPS

A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

MULTI-BEAM LASER POWER CONTROL CIRCUIT AND IMAGE FORMING APPARATUS USING THE SAME

A disclosed multi-beam laser power control circuit includes a light receiving element receiving power output from semiconductor lasers to control output power of a semiconductor laser array having plural semiconductor lasers, automatic power control circuits (APC circuits) controlling emission power output from semiconductor lasers based on received corresponding automatic power control execution signals so as to be set to predetermined emission power based on output from the light receiving element, and APC execution signal input terminals inputting the corresponding automatic power control execution signals, wherein, when plural APC execution signals input to the corresponding APC execution signal input terminals are overlapped, the automatic power control circuits (APC circuits) to be preferentially operated is determined based on input timings of the APC execution signals and operated.

OPTICAL COMMUNICATION LIGHT SOURCE UNIT AND WAVELENGTH MONITORING CONTROL METHOD

An optical communication light source unit comprises first means which comprises a light emitting device and emits light; second means for automatically controlling drive current or optical output power of the light emitting device to maintain the drive current or optical output power at a given target value; and third means for automatically controlling device temperature of the light emitting device to maintain the device temperature at a given target value. The optical communication light source unit further comprises fourth means for storing a first relationship among the drive current, device temperature, and optical output wavelength of the light emitting device and a second relationship among the drive current, device temperature, and optical output power of the light emitting device. The first relationship is determined by a value concerning the drive current, device temperature, and optical output wavelength of the light emitting device, and the second relationship is determined ...

OPTICAL AMPLIFIERS

A semiconductor travelling wave optical amplifier is presented in a new configuration. An amplifier chip has the rear facet provided with a reflective coating. Optical signals are input and amplified signals are output via optical fibres and directional coupler. A single fibreto-amplifier alignment is required between fibre tail and the front facet. The front facet is provided with a very low reflectivity coating. In this configuration the amplification is increased in comparison with the conventional in-line amplifier configuration.

OPTICAL PACKAGE

A lens assembly for focussing the light output of a device 2 on to a target 4, when there is relative movement between the target and device. The assembly comprises a pair of lenses with the device at the focus of the first and the target in the focal range of the second lens.

SEMICONDUCTOR LASER DRIVING DEVICE FOR STABILIZING THE OPTICAL OUTPUT THEREOF

In a laser driving device for stabilizing the optical output level of a semiconductor laser, a drive circuit supplies a drive current signal to the laser. A monitoring photodiode is provided for partially receiving the optical laser output to produce an electrical monitor signal indicative of the actual output level of the laser. A differential amplifier is connected to the photodiode to serve as a comparator for receiving a reference signal indicative of a reference output level of the laser, and for detecting a difference between values of the monitor signal and the reference signal to produce a comparison signal indicative of a change in the actual optical output level of the laser. An abnormal current eliminator is connected to the comparator, for, when the laser is disenergized or just after it is driven to become operative, controlling the comparator so that the comparison signal has a limited amplitude, whereby a current component undesirably supplied as the driven current to the ...

POWER SUPPLY SYSTEM FOR A SEMICONDUCTOR LIGHT SOURCE

LASER DIODE DRIVE SYSTEM

A laser diode drive system for generating a drive current for a laser diode is described. The laser diode drive system comprises a first laser diode driver connected to the laser diode by a first cable to provide a drive current source for the laser diode. A second laser diode driver is then connected to the laser diode by a second cable to provide a low current sink for the laser diode. A feedback control loop is employed to provide a feedback signal for the second laser diode driver from to sample of an output field of the laser diode. The laser diode drive system exhibits low power consumption while being capable of creating sufficient feedback bandwidth to reduce the excess optical noise by at least an order of magnitude at 1 MHz compared with laser diode drive systems comprising just a first laser diode driver.

OPTICAL COMMUNICATION DEVICE

An optical communication device (an LD module or an LD/PD module) having a flat substrate, a light waveguide layer formed upon the substrate with a core for guiding signal LD light, an LD bonded upon a part of the substrate without the whole or a part of the light waveguide layer for producing signal front light and monitoring rear light, a path conversion groove being perforated along the core on the substrate behind the LD and having slanting walls for reflecting rear light emitted backward from the LD, a bottom- or top- incidence type PD bonded upon the light waveguide layer over the path conversion groove for monitoring the LD power by detecting the LD rear light reflected by the path conversion groove. Since the PD level is higher than the LD by the thickness of the light waveguide layer, the monitoring PD can sense more than 50% of the LD rear light.

PHASE-CONTROL IN AN EXTERNAL-CAVITY TUNEABLE LASER

The present invention relates to a single-mode external-cavity tuneable laser including a gain medium, a tuneable element and a channel allocation grid element. The channel allocation grid element is preferably a FP etalon, which is structured and configured to define a plurality of equally spaced transmission peaks corresponding to the ITU channel grid, e.g., 200, 100, 50 or 25 GHz. The tuneable element, preferably a tuneable mirror, serves as the coarse tuning element that discriminates between the peaks of the grid etalon. The tuneable laser of the invention has a relatively short cavity length of not more than 15 mm, preferably not larger than 12 mm. It has been found that the FP etalon introduces a phase non-linearity in the external cavity, which induces a compression of the cavity modes, i.e., a reduction in the cavity mode spacing, in correspondence to the etalon transmission peaks. Mode compression increases with the decrease of the FWHM bandwidth of the grid FP etalon, hereafter ...

DEVICE PACKAGE AND METHODS FOR THE FABRICATION AND TESTING THEREOF

Provided are methods of foaming sealed via structures. One method involves: (a) providing a semiconductor substrate having a first surface and a second surface opposite the first surface; (b) forming a layer on the first surface of the substrate; (c) etching a via hole through the substrate from the second surface to the layer, the via hole having a first perimeter at the first surface; (d) forming an aperture in the layer, wherein the aperture has a second perimeter within the first perimeter; and (e) providing a conductive structure for sealing the via structure. Also provided are sealed via structures, methods of detecting leakage in a sealed device package, sealed device packages, device packages having cooling structures, and methods of bonding a first component to a second component.

LASER PULSE POSITION MONITOR FOR SCANNED LASER EYE SURGERY SYSTEMS

... ²²²Devices, systems, and methods for measuring and determining positions of light ²energy having wavelengths of less than (as well as equal to or greater than) ²200 nm, and are particularly well suited for measuring pulsed light at ²ultraviolet and other wavelengths using position sensing diode (PSD) ²technology. An integrator may sum a total charge of a signal from the PSD. ²Correlations between a distribution of integrated charges among electrodes of ²the PSD may be non-linear, and may benefit from adjustment for different ²overall pulse light quantities and/or spot sizes.² ...

DEVICE PACKAGE AND METHODS FOR THE FABRICATION AND TESTING THEREOF

Provided are optoelectronic device packages. The packages include a base substrate having an optoelectronic device mounting region on a surface of the base substrate and a lid mounting region. An optoelectronic device is mounted on the optoelectronic device mounting region. A lid is mounted an the lid mounting region to form an enclosed volume between the base substrate and the lid. The optoelectronic device is in the enclosed volume. The lid has an optically transmissive region suitable for transmitting light of a given wavelength along an optical path to or from the optoelectronic device, wherein at least a portion of the lid mounting region is disposed along the optical path below the surface of the base substrate to a depth below the optical path. Also provided are wafer or grid level optoelectronic device packages, wafer- or grid-level optoelectronic device package lid and their methods of formation, and connectorized optoelectronic devices.

TRANSMITTER PHOTONIC INTEGRATED CIRCUITS (TXPIC) AND OPTICAL TRANSPORT NETWORKS EMPLOYING TXPICS

... ²²²A photonic integrated circuit (PIC) chip comprising an array of modulated ²sources, each providing a modulated signal output at a channel wavelength ²different from the channel wavelength of other modulated sources and a ²wavelength selective combiner having an input optically coupled to received ²all the signal outputs from the modulated sources and provide a combined ²output signal on an output waveguide from the chip. The modulated sources, ²combiner and output waveguide are all integrated on the same chip.² ...

VCSEL POWER MONITORING SYSTEM USING PLASTIC ENCAPSULATION TECHNIQUES

A plastic encapsulated VCSEL and power monitoring system wherein the VCSEL and photodetector are encapsulated in an optoelectronic plastic molding material. A tilted window, with a partially reflective coating on one side, is attached to the top of the plastic molding material using an epoxy with a refractive index that substantially matches the molding material. The plastic encapsulated VCSEL and photodetector may be manufactured at low cost using standard molding techniques. The high optical quality of the tilted window and partially reflective coating provide an excellent surface to reflect a portion of the optical beam back to the photodetector. Also, the tilted window substantially reduces inconsistent power monitoring due to beam divergence and walk-off.

METHOD AND APPARATUS FOR CONTROLLING OPTICAL POWER

The present application provides a method for controlling optical power, the method includes : monitoring output optical power of an optical source, and judging whether a preset test control signal is received; when the preset test control signal is not received, modulating a data signal to output light of the optical source, and adjusting a bias current of the optical source according to an output optical power monitoring result of the optical source to implement automatic power control; and when the preset test control signal is received, starting a test and superimposing a test signal to the data signal to form a superimposed signal and modulating the superimposed signal to the output light of the optical source, the output optical power monitoring result of the optical source is ignored during the test period to maintain the bias current of the optical source at a preset target value. The present application further provides an apparatus for controlling optical power.

Method and Apparatus for Back Facet Monitoring of Multiple Semiconductor Laser Diodes

CURRENT CONTROL FOR AN ANALOG OPTICAL LINK

A control circuit for an injection laser provides a pre-bias current which prevents clipping induced errors in the laser output. An analog modulating signal is provided directly to the laser which receives the sum of a feedback current (Ifb) and a current source (Io) as the pre-bias current (Ipb). A monitor diode detects the laser light output and provides a current (Idet). A feedback circuit operates in a limited dynamic range, e.g. I~ +/- 40 mA or is incapable of outputting a negative current (Ifb>0). The feedback circuit responds to changes in Idet and adjusts the laser pre-bias current to hold Idet equal to a preset value, which effectively holds the laser's average output power constant. If the pre-bias current necessary to hold Idet fixed falls below some minimum level, Imin, the feedback circuit will run out of dynamic range and the laser's average power will increase. By preventing Ipb from falling below Imin clipping induced errors and distortion are avoided.

DIFFRACTIVE VERTICAL CAVITY SURFACE EMITTING LASER POWER MONITOR AND SYSTEM

A power monitor for a light emitter emitting from a single face creates a monitor beam by deflecting a portion of the application beam and further manipulating the monitor beam to allow more efficient use of the monitor beam. For example, the monitor beam may be collimated to allow an increase in spacing between the light emitter and a detector for sensing the monitor beam. Alternatively or additionally, the monitor beam may be focused to allow use of a smaller detector and of a smaller percentage of the application beam. The diffractive element deflecting the beam may be either transmissive or reflective. The additionally manipulation of the monitor beam may be provided by the same diffractive element which deflects the beam, which is particularly useful when the diffractive element is reflective, and/or by additional optical elements.

Anordnung zur Erzeugung rauscharmer Laser-Strahlung von elektrisch angeregten Festkörper-Lasern

ARRANGEMENT FOR THE REGULATION OF THE POWER OUTPUT OF A DIODE LASER.

DIODE LASER ARRANGEMENT.

Procedure and device for the regulation of a source of light.

Drive electronics and method for laser drive control.

Die Erfindung betrifft eine Treiberschaltung zur Erzeugung eines Stromflusses durch eine Lichtquelle (5), insbesondere Laserdiode (LD), und ein Verfahren zum Betrieb der Treiberschaltung, wobei in einem Stromkreis (2) eine Spannungsquelle (3), die Lichtquelle (5), ein Vorwiderstand und ein Schalter angeordnet sind, wobei zur Erzeugung eines in diskreten Stufen steuerbaren oder regelbaren Vorwiderstands für die Lichtquelle (5) der Stromkreis (2) in mindestens zwei parallele Stromzweige (21, ..., 2N) verzweigt ist und in jedem Stromzweig (21, ..., 2N) jeweils mindestens ein zuschaltbarer Parallelwiderstand (R1,...,RN) vorhanden ist.

Coaxial cooled laser modules with integrated thermal electric cooler and optical components

Electronic component mounting package for the package body and electronic device

Temperature control multi-channel light emitting sub-module and optical transceiver module with same

Pulse oscillation solid-sate laser apparatus and laser machining apparatus

Laser energy control system and method

Optical element module package and method for manufacturing the same

Direct diode laser processing device and its output monitoring method

SAFETY DEVICE Of a LASER DIODE

Optical amplifier regulated.

DEVICE OF STABILIZATION OF the OPTICAL POWER Of a SEMICONDUCTOR LASER

DISPOSITIF DE PROTECTION D'UNE DIODE LASER

LE DISPOSITIF DE PROTECTION D'UNE DIODE LASER 1 ALIMENTEE PAR LA SUPERPOSITION D'UN COURANT CONTINU DE POLARISATION I ET D'UN COURANT VARIABLE PORTEUR D'INFORMATIONSDI, A TRAVERS UN SYSTEME DE CONTRE-REACTION OPTOELECTRONIQUE 2 ET 3 COMPORTE UNE RESISTANCE VARIABLE 10 CONNECTEE EN AMONT DE LA DIODE LASER 1 ET DU SYSTEME DE CONTRE-REACTION 2 ET 3 DE MANIERE A FORMER UNE BOUCLE FERMEE AVEC LA SOURCE 8 DE COURANT PORTEUR D'INFORMATIONSDI, ET DESTINE A S'ASSURER DE LA POLARISATION DE LA DIODE LASER AVANT TOUTE INJECTION DE COURANT PORTEUR D'INFORMATIONS DANS CETTE DIODE. APPLICATION AUX SYSTEMES VIDEODISQUES.

Optical device with semiconductors

Un dispositif à semiconducteurs optique (50) comprend un élément semiconducteur (4) qui émet ou reçoit de la lumière et un boîtier (3, 12) pour enfermer hermétiquement cet élément. Le boîtier comprend une fenêtre en silicium (1) qui transmet sélectivement la lumière reçue ou émise par l'élément semiconducteur. La fenêtre est fixée au corps de boîtier (3) à l'aide d'une brasure (2) qui forme un alliage eutectique avec le silicium, grâce à quoi la jonction entre la fenêtre et le corps de boîtier est protégée contre des influences externes. En outre, l'intérieur du boîtier n'est pas visible de l'extérieur après la fabrication du dispositif.

OPTICAL SOURCE HAS CONTROL SYSTEM

Un dispositif d'émission optique comprend une source laser (2) présentant une surface d'émission et un capteur (3) adjacent latéralement à ladite source, émettant un signal de sortie dépendant de la quantité de lumière reçue par sa surface de détection. Un guide d'onde (7) transparent est placé devant la surface d'émission (5), essentiellement parallèlement à celle-ci, de sorte que la lumière frappant le guide d'onde perpendiculairement à la surface d'émission traverse perpendiculairement le guide d'onde. Un moyen de couplage (8) est prévu entre la surface d'émission et le guide d'onde. Un élément dispersant dans ledit moyen de couplage permet qu'une partie de la lumière laser frappe le guide d'onde selon un angle oblique et pénètre dans ce dernier pour être transportée jusqu'au capteur.

DEVICE, IN PARTICULAR HAS SEMICONDUCTOR, FOR THE TREATMENT OF TWO WAVES, IN PARTICULAR LUMINOUS

Ce dispositif peut comporter, sur un même substrat semi-conducteur d'In P (6): - un émetteur laser (H1) pour émettre des ondes (WE) ayant une première longueur d'onde telle que 1 300 nm, - une photodiode (H2) pour recevoir et détecter des ondes (WR) ayant une deuxième longueur d'onde telle que 1 550 nm, et - un séparateur (G) absorbant les ondes ayant la première longueur d'onde, ce séparateur étant interposé entre l'émetteur laser (H1) et la photodiode (H2) pour protéger cette photodiode contre les ondes ayant la première longueur d'onde. Selon l'invention des moyens de mesure d'absorption (Q) fournissent un signal (iG) représentatif de la puissance des ondes absorbées par le séparateur. Ce signal permet de réguler le fonctionnement de l'émetteur laser (H1). L'invention s'applique notamment à la réalisation de dispositifs d'extrémité à installer chez des abonnés de réseaux locaux interactifs à fibres optiques.

Optical semiconductor module, useful for multimedia optical networks, comprises a resin gel covering an optical semiconductor element and filling the light transmission space between the element and an optical element

Un élément à ID=2.1 HE=3 WI=32 LX=840 LY=1062>>semiconducteursemi conducteur> optique (3) et un élément optique (2) comportant une facette de couplage optique sont disposés sur une surface de support d'une plate-forme (1). L'élément optique est couplé optiquement à l'élément à semiconducteur optique au niveau de la facette de couplage optique. Un élément de protection (6) recouvre l'élément à semiconducteur optique et est disposé au moins dans une zone de transmission de lumière dans un espace entre l'élément à semiconducteur et la facette de couplage optique de l'élément optique. L'élément de protection (6) est réalisé en une résine de modification acrylique constituant un gel. Un module à semiconducteur optique présentant une résistance suffisante à l'humidité et convenant pour un coût faible est constitué.

INFRA-RED SOURCE OF LIGHT INCLUDING/UNDERSTANDING a LASER HAS SEMICONDUCTOR ASSOCIATES HAS MEANS OF SELECTION OF MODE AND CONTROL IN POWER

LASER HAS EMISSION ON THE SURFACE HAS SURGES VERTICAL AND SURVEILLANCE DEVICE OF EXIT IN COMBINATION AND ITS MANUFACTORING PROCESS

Une combinaison constituée par un laser à émission en surface à cavité verticale (VCSEL) (20) et par une diode de surveillance (10) présentant une valeur de capacité parasite réduite est destinée à être utilisée dans des systèmes de communication à bande passante élevée. Le VCSEL comporte à la fois des contacts de type p et de type n sur la même face. Ceci permet le montage du VCSEL sur une puce ou diode de surveillance sans utiliser de couche de contact métallique. Selon un mode de réalisation dans lequel le VCSEL est soudé sur la puce de surveillance pour assurer une stabilité mécanique, seulement un petit plot métallique pas plus large que le VCSEL est utilisé. La réduction en termes de métallisation conduit à une valeur de capacité parasite plus faible, ce qui à son tour conduit à des vitesses de fonctionnement potentielles plus élevées.

MANUFACTORING PROCESS Of a LASER FILM OF REFLEXION AND DEVICES AND OPTICS USING FILM OF REFLEXION

Le procédé de fabrication d'un film de réflexion (55), ayant une réflectivité équivalente dans des milieux présentant des indices de réfraction différents, comprend les étapes de préparation d'un milieu optique (51) comportant une surface de réflexion et présentant un indice de réfraction n0 , et de détermination d'une longueur d'onde de la lumière destinée à être réfléchie. Le procédé comprend, en outre, une étape d'empilement de plusieurs paires de couches (52, 53) constituées par une première couche (52) présentant un indice de réfraction n1 et par une seconde couche (53) présentant un indice de réfraction n2 sur la surface de réflexion du milieu optique (51). Une troisième couche (54) présentant l'indice de réfraction n1 est ensuite formée sur la surface de la seconde couche (53) de la dernière paire de couches (52, 53).

OPTICAL MODULE HERMETICALLY PACKAGED IN MICRO-MACHINED STRUCTURES

SEMICONDUCTOR INTEGRATED CIRCUITS AND OPTICAL PICKUP OPTICAL SYSTEM UNIT INCLUDING THE SAME AND OPTICAL PICKUP DEVICE

Laser System with Dynamically Stabilized Transient Wavelength and Method of Operating Same

A method and laser system for dynamically adjusting a transient wavelength of light pulses emitted by a laser includes sequential processing of transient photocurrent curves which are generated after interaction between each light pulse and wavelength-selective medium which is configured with a known spectral peak line selected in the range of the transient wavelength. The method further includes continuously processing parameters of sequentially generated curves until the processed parameters are repeatedly uniform.

Semiconductor laser driver and image forming apparatus incorporating same

A semiconductor laser driver to execute automatic power control (APC) for multiple semiconductor lasers based on a common APC output from an image controller. The semiconductor laser driver includes a drive circuit to generate an individual APC signal to execute APC for each semiconductor laser based on the common APC signal.

Automatic power control (apc) loop for adjusting the bias current of a laser diode

A automatic power control loop comprises a photo diode used for sensing a light intensity of a laser diode to generate a feedback current, a switch selector used for selecting one among a plurality of predetermined currents according to a control signal generated by a controller, a transducer used for transferring a current different between the feedback current and the selected predetermined current into a load voltage, a comparator used for comparing the load voltage with a reference voltage to generate a comparison signal, a counter used for counting a count value according to the comparison signal and the control signal, and a laser diode driver used for generating a corresponding bias current in response to the count value to drive the laser diode. Thereby, the bias current will be adjusted within an allowable range, so that the light source of the laser diode can maintain a constant light intensity.

Edge-emitting semiconductor laser

The invention relates to an edge-emitting semiconductor laser comprising a semiconductor body ( 10 ), which comprises a waveguide region ( 4 ), wherein the waveguide region ( 4 ) comprises a first waveguide layer ( 2 A), a second waveguide layer ( 2 B) and an active layer ( 3 ) arranged between the first waveguide layer ( 2 A) and the second waveguide layer ( 2 B) and serving for generating laser radiation ( 5 ), and the waveguide region ( 4 ) is arranged between a first cladding layer ( 1 A) and a second cladding layer ( 1 B) disposed downstream of the waveguide region ( 4 ) in the growth direction of the semiconductor body ( 10 ). The waveguide region ( 4 ) has a thickness d of 400 nm or less, and an emission angle of the laser radiation ( 5 ) emerging from the semiconductor body ( 10 ) in a direction parallel to the layer plane of the active layer ( 3 ) and the emission angle of the laser radiation ( 5 ) emerging from the semiconductor body ( 10 ) in a direction perpendicular to the layer plane of the active layer ( 3 ) differ from one another by less than a factor of 3.

Method, Circuitry and Apparatus for Outputting a Stable Optical Signal in a Dense Wavelength Division Multiplexing Device During Fast Changes of Operating Conditions

The disclosure relates to a fast and stable method of output wavelength control in a DWDM optical device, and a circuit configured to perform the method. The method and circuit can control of timing and overshoot during conditions of rapid operational changes, such as during power-on or restart of the device. The method and circuit includes optimized APC, TEC and electro-absorption (EA) modulator control hardware and algorithms, to effectively control transient processes. In the present disclosure, software and circuitry based on the method(s) are achieved in part by optimizing APC, EA and TEC control algorithms. The present disclosure combines low-cost methodology and hardware. In combination with hardware/circuit optimization, one can achieve fast turn-on of an optical output signal at a stable wavelength. The method and circuit provides a stable power-up process in which a change of wavelength is small enough to meet DWDM specification requirements, to ensure the elimination and avoidance of crosstalk in adjacent channels in dense wave (sub)systems.

Laser module

[Objective] To prevent change in a direction of an optical axis of a split light within a plane parallel to a surface on which the beam splitter is installed. [Means] A laser module including a laser light source that emits a laser light and a beam splitter that splits a portion of the laser light emitted from the laser light source. The beam splitter includes a first reflective surface and a second reflective surface that are parallel to each other. The first reflective surface transmits a first portion of the laser light and reflects a second portion of the laser light to the second reflective surface. The second reflective surface receives the second portion of the laser light from the first reflective surface and reflects received laser light in a direction parallel to the laser light emitted from the laser light source.

Vertical cavity surface emitting laser with active carrier confinement

It is an object of the present invention to improve the confinement of the carriers within a VCSEL. As a general concept of the invention, it is proposed to integrate a phototransistor layer structure into the layer stack of the VCSEL.

Optical pickup apparatus, integrated circuit, and method for controlling laser output of optical pickup apparatus

An optical-pickup apparatus includes: a first laser light source including a first laser diode to emit a laser beam having a first wavelength, and a back-monitor photodetector to receive the laser beam emitted in a backward direction, not being an optical-disc direction, and output a first monitor signal; a second laser-light source including a second laser diode to emit a laser beam having a second wavelength; a light-receiving circuit including a front-monitor photodetector to receive the laser beam emitted in a forward direction, being the optical-disc direction, and output a second monitor signal, and a switch circuit to be inputted with the first and second monitor signals, and output the first or second monitor signal according to a switch signal; and first and second drive circuits to drive the first and second laser diodes according to the first and second monitor signals outputted from the light-receiving circuit, respectively.

Quantum interference device, atomic oscillator, and magnetic sensor

A quantum interference device includes: gaseous alkali metal atoms; and a light source for causing a resonant light pair having different frequencies that keep a frequency difference equivalent to an energy difference between two ground states of the alkali metal atoms, the quantum interference device causing the alkali metal atoms and the resonant light pair to interact each other to cause an electromagnetically induced transparency phenomenon (EIT), wherein there are a plurality of the resonant light pairs, and center frequencies of the respective resonant light pairs are different from one another.

Method to switch emission wavelength of tunable laser diode

The method to change the emission wavelength of a tunable LD is disclosed. In an ordinary state, the method monitors conditions not only relating to determine the emission wavelength but conditions independent of the emission wavelength by an ordinary A/D-C implemented within the controller. Responding to an instruction to switch the emission wavelength, the controller only monitors the former conditions affecting the determination of the emission wavelength. The sampling rate of the ordinary A/D-C is equivalently enhanced without installing an additional A/D-C.

CONTROL METHOD AND MEASURING METHOD OF SEMICONDUCTOR OPTICAL AMPLIFIER, AND SEMICONDUCTOR OPTICAL AMPLIFIER DEVICE

A control method of a semiconductor optical amplifier includes: controlling a driving current of the semiconductor optical amplifier in a region where a light output intensity decreases in accordance with increasing of the driving current, a drive current in the region being higher than a drive current in a region where a light output intensity increases in accordance with increasing of the driving current. 1. A control method of a semiconductor optical amplifier comprising:controlling a driving current of the semiconductor optical amplifier in a region where a light output intensity decreases in accordance with increasing of the driving current, a drive current in the region being higher than a drive current in a region where a light output intensity increases in accordance with increasing of the driving current.2. The control method according to claim 1 , whereinthe semiconductor optical amplifier has output characteristics including a first region in which a light output intensity increases with increase in driving current, a second region in which a driving current is higher than that in the first region and the light output intensity reaches saturation with increase in driving current, and a third region in which the driving current is higher than that in the second region and the light output intensity decreases with increase in driving current, andthe driving current of the semiconductor optical amplifier is in the third region.3. The control method according to claim 1 , whereina light output intensity of the semiconductor optical amplifier is 0.4 dB or more smaller than a peak of the light output intensity of the semiconductor optical amplifier.4. The control method according to claim 1 , whereina light source of the semiconductor optical amplifier is intensity-modulated light beam.5. The control method according to claim 1 , whereinthe driving current is feedback-controlled to a target value of a light output intensity of the semiconductor optical ...

Small packaged tunable laser assembly

A tunable laser configured in a small package coupled to a printed circuit board. The tunable laser includes a housing with a volume formed by exterior walls. An electrical input interface is positioned at the first end of the housing. An optical output interface is positioned at the second end of the housing and configured to transmit a continuous wave optical beam. A beam splitter and photodiode is disposed in the path of the laser beam for determining the emitted intensity of the laser beam, and an optical isolator is positioned downstream of the beam splitter to prevent the incoming light from the beam splitter from reflecting back though the beam splitter and into the cavity of the laser.

Light source apparatus and lighting apparatus

A laser lighting module includes a base part, a laser diode which is a blue laser device, a substrate with which the laser diode is in contact, a ceramic phosphor which reflects light entering from the laser diode to thereby change a direction of the light and is excited by the light to generate yellow fluorescence, and a lens for adjusting luminous intensity distribution of light emitted from the ceramic phosphor. The substrate is formed of a material which is thin and has excellent thermal conductivity, and is in surface contact with the laser diode and the base part. In the laser lighting module, since the substrate serves as a device heat radiator, it is possible to easily remove the heat generated by the laser diode.

PULSE LIGHT SOURCE

The pulse light source comprises a semiconductor laser outputting pulse light, an optical filter, and an optical amplifier. The optical filter outputs a chirping component of the inputted pulse light, by adjusting a relative position of a transmission spectrum of the optical filter with respect to an output spectrum of the seed light source. 1. A pulse light source , comprising:a semiconductor laser which is directly modulated and outputs pulse light;a first optical filter which inputs the pulse light from the semiconductor laser and selectively outputs a chirping component of the inputted pulse light, the first optical filter being provided on an optical path between the semiconductor laser and an output end of the pulse light source:a first optical amplifier which inputs the pulse light from the semiconductor laser and amplifies the inputted pulse light, the first optical amplifier being provided on the optical path between the semiconductor laser and the output end.2. The pulse light source according to claim 1 , wherein the semiconductor laser outputs the pulse light that overshoots at a rising thereof.3. The pulse light source according to claim 1 , wherein a center wavelength of a transmission spectrum of the first optical filter is adjustable.4. The pulse light source according to claim 3 , wherein the center wavelength of the transmission spectrum of the first optical filter is set in a long wavelength side from a peak wavelength of the pulse light.5. The pulse light source according to claim 3 , wherein the transmission spectrum of the first optical filter has a full width at half maximum of 3 nm.6. The pulse light source according to claim 1 , wherein the optical filter is provided on an optical path between the semiconductor laser and the first optical amplifier.7. The pulse light source according to claim 6 , further comprising a second optical amplifier provided on an optical path between the semiconductor laser and the first optical filter.8. The pulse ...

Method and Apparatus for Controlling Optical Power

A method can be used for controlling optical power. Output optical power of an optical source is monitored and it is determined whether a preset test control signal is received. When the preset test control signal is not received, a data signal is modulated to output light of the optical source and a bias current of the optical source is adjusted according to an output optical power monitoring result of the optical source to implement automatic power control. When the preset test control signal is received, a test is started and a test signal is superimposed to the data signal to form a superimposed signal. The superimposed signal is modulated to the output light of the optical source. The output optical power monitoring result of the optical source is ignored during the test period to maintain the bias current of the optical source at a preset target value.

Light source, and optical coherence tomography module

An optical module includes a light source. The light source can be a swept wavelength light source, and optical module includes a wavemeter. The wavemeter includes a wavemeter tap capable of directing a wavemeter portion of light produced by the light source away from a main beam, a wavelength selective filter arranged to receive the wavemeter portion, a first wavemeter detector arranged to measure a transmitted radiation intensity of radiation transmitted through the filter, and a second wavemeter detector arranged to measure a non-transmitted radiation intensity of radiation not transmitted through but reflected by the filter. In addition, an optical coherence tomography apparatus includes the optical module.

Amplifying apparatus and amplifying medium

An amplifying apparatus includes an optical fiber that includes a wound portion doped with a rare earth element and three-dimensionally wound, holes being formed in cladding of the optical fiber and surrounding a core of the optical fiber, the optical fiber transmitting signal light injected thereinto; a thermally conductive member in which the wound portion of the optical fiber embedded, the thermally conductive member having thermal conductivity; a light source that emits excitation light; an injecting unit that injects the excitation light emitted by the light source, into the optical fiber; and a temperature adjusting unit that includes a thermal coupling unit thermally connected to the light source and the thermally conductive member, the temperature adjusting unit adjusting a temperature of the thermal coupling unit.

LASER ASSEMBLY PACKAGING FOR SILICON PHOTONIC INTERCONNECTS

Processes and apparatuses described herein reduce the manufacturing time, the cost of parts, and the cost of assembly per laser for photonic interconnects incorporated into computing systems. An output side of a laser assembly is placed against an input side of a silicon interposer (SiP) such that each pad in a plurality of pads positioned on the output side of the laser assembly is in contact with a respective solder bump that is also in contact with a corresponding pad positioned on the input side of the SiP. The laser assembly is configured to emit laser light from the output side into an input grating of the SiP. The solder bumps are heated to a liquid phase. Capillary forces of the solder bumps realign the laser assembly and the SiP while the solder bumps are in the liquid phase. The solder bumps are then allowed to cool. 1. A method comprising:placing an output side of a laser assembly against an input side of a silicon interposer (SiP) such that each pad in a plurality of pads positioned on the output side of the laser assembly is in contact with a respective solder bump that is also in contact with a corresponding pad positioned on the input side of the SiP, wherein the laser assembly comprises a laser diode and is configured to emit laser light from the output side, and wherein the SiP comprises an input grating configured to redirect the laser light through a silicon layer of the SiP;heating the solder bumps to at least a first temperature at which the solder bumps change from a solid phase to a liquid phase;allowing capillary forces of the solder bumps to realign the laser assembly and the SiP while the solder bumps are in the liquid phase; andcooling the solder bumps to a second temperature below the first temperature such that the solder bumps change from the liquid phase to the solid phase, wherein the solder bumps couple the laser assembly to the SiP when the cooling is completed, wherein the output side of the laser assembly comprises an output ...

MODULATED LIGHT SOURCE

A modulated light source includes a ring modulator, a first optical waveguide and a second optical waveguide that are optically connected to the ring modulator, and a third optical waveguide that optically connects an end of the first optical waveguide and an end of the second optical waveguide. At least part of the third optical waveguide has optical gain, and an optical waveguide loop including the ring modulator, the first optical waveguide, the second optical waveguide, and the third optical waveguide is used as a resonator to cause laser oscillation. 1. A modulated light source comprising:a ring modulator;a first optical waveguide and a second optical waveguide that are optically connected to the ring modulator; anda third optical waveguide that optically connects an end of the first optical waveguide and an end of the second optical waveguide,wherein at least part of the third optical waveguide has optical gain, andan optical waveguide loop including the ring modulator, the first optical waveguide, the second optical waveguide, and the third optical waveguide is used as a resonator to cause laser oscillation.2. The modulated light source according to claim 1 , wherein a transmission wavelength band between the end of the first optical waveguide and the end of the second optical waveguide has a size that allows selecting one of a plurality of longitudinal modes in which laser oscillation is possible to occur claim 1 , and the laser oscillation occurs in a single longitudinal mode.3. The modulated light source according to claim 1 ,wherein the first optical waveguide has another end having a mirror, andthe second optical waveguide has another end serving as a light output port.4. The modulated light source according to claim 1 , including a plurality of optical waveguide loops each identical to the optical waveguide loop claim 1 ,wherein in two adjacent optical waveguide loops out of the optical waveguide loops, another end of the second optical waveguide of one ...

COMPACT TUNABLE LASER DEVICE

The present invention relates to a compact tunable laser device that can change the oscillation laser wavelength. The laser device includes: a laser diode chip that emits laser light; an optical feedback-partial reflective mirror that feeds some of light emitted from the laser diode chip back to the laser diode chip by reflecting it; a collimating lens that is disposed in a light path between the laser diode chip and the optical feedback-partial reflective mirror and collimates light emitted from the laser diode chip a tunable-selective filter of which the transmissive wavelength changes in accordance with temperature; and a 45°-reflective mirror that changes laser light traveling horizontally to a package bottom into laser light traveling perpendicular to the package bottom, wherein the laser diode chip or the tunable-selective filter is disposed on a thermoelectric element and has an oscillation wavelength changing in accordance with a change in temperature of the thermoelectric element 1. A semiconductor laser device comprising:{'b': '100', 'a laser diode chip () that emits laser light;'}{'b': 500', '100', '100, 'an optical feedback-partial reflective mirror () that feeds some of light emitted from the laser diode chip () back to the laser diode chip () by reflecting it;'}{'b': 200', '100', '500', '100, 'a collimating lens () that is disposed in a light path between the laser diode chip () and the optical feedback-partial reflective mirror () and collimates light emitted from the laser diode chip ();'}{'b': '300', 'a tunable-selective filter () of which the transmissive wavelength changes in accordance with temperature; and'}{'b': '400', 'a 45°-reflective mirror () that changes laser light traveling horizontally to a package bottom into laser light traveling perpendicular to the package bottom,'}{'b': 100', '300', '900', '900, 'wherein the laser diode chip () or the tunable-selective filter () is disposed on a thermoelectric element () and has an oscillation ...

INTEGRATED INTER-CAVITY PHOTODETECTOR FOR LASER POWER AND THRESHOLD ESTIMATION

A multi-section laser device is configured with a gain section and an integrated photodetector section. The photodetector section, rather than being a separate component, is integrated directly into the body of the laser. The integrated photodetector section absorbs photons generated by the gain section and creates a photocurrent that is proportional to the output of the multi-section laser device. The measured photocurrent is usable to calculate power output of the multi-section laser device and to identify any adjustments that may be needed to be made to the laser in order to achieve desired laser light output. 1. A multi-section laser device comprising:a gain section that is electrically biased in a forward direction; anda photodetector section that is electrically biased in a reverse direction, the photodetector section being controllable independently of the gain section;wherein the photodetector section is configured to absorb a portion of the photons generated by the gain section and to generate photocurrent that is proportional to an output power of the multi-section laser device such that the photodetector section is usable to determine the output power of the multi-section laser device.2. The multi-section laser device according to claim 1 , wherein the photodetector section is positioned between the gain section and a light emitting facet of the multi-section laser device.3. The multi-section laser device according to further comprising an unpumped section claim 2 , wherein the photodetector section is positioned directly adjacent to the unpumped section of the multi-section laser claim 2 , such that the photodetector section and the unpumped section share a common bounding edge.4. The multi-section laser device according to claim 1 , wherein the gain section is positioned between the photodetector section and a light emitting facet of the multi-section laser device.5. The multi-section laser device according to claim 1 , wherein the photodetector section ...

OPTICAL MODULE

An optical module includes a semiconductor laser element, a lens configured to collect emitted light that is emitted from the semiconductor laser element, a cap configured to hold the lens and hermetically seal the semiconductor laser element, a monitor light-receiving element configured to receive backlight of the semiconductor laser element, a transmission plate arranged between the semiconductor laser element and the monitor light-receiving element and configured to attenuate the backlight according to decrease in a temperature around the cap so as to cause the backlight to enter the monitor light-receiving element, and a control unit configured to control an injection current of the semiconductor laser element such that an output of the monitor light-receiving element is kept at a constant level. 1. An optical module comprising:a semiconductor laser element;a thermoelectric cooler configured to controls the temperature of the semiconductor laser element at a constant level;a lens configured to collect emitted light that is emitted from the semiconductor laser element;a stem, the thermoelectric cooler is fixed to the stem;a metal post fixed to the stem;a cap configured to hold the lens and hermetically seal the semiconductor laser element, the cap is fixed to the stem;a monitor light-receiving element configured to receive backlight of the semiconductor laser element;a transmission plate arranged between the semiconductor laser element and the monitor light-receiving element and configured to attenuate the backlight according to decrease in a temperature of the transmission plate so as to cause the backlight to enter the monitor light-receiving element, the transmission plate is away from both the semiconductor laser element and the monitor light-receiving element, the transmission plate is fixed to the metal post;a controller configured to control an injection current of the semiconductor laser element such that an output of the monitor light-receiving element ...

METHOD OF EVALUATING INITIAL PARAMETERS AND TARGET VALUES FOR FEEDBACK CONTROL LOOP OF WAVELENGTH TUNABLE SYSTEM

A method of determining initial parameters and target values for tuning an emission wavelength of a wavelength tunable laser capable of emitting laser light in a substantial wavelength range is disclosed. The method iterates an evaluation of initial parameters and target values at target wavelengths in a preset order. The evaluation includes steps of supplying empirically obtained parameters to the t-LD, confirming whether the t-LD generates an optical beams, determining the initial parameters and the target values by carrying out feedback loops of the AFC and the APC when the t-LD generates the optical beam, or shifting the wavelength range so as to exclude the current target wavelength when the t-LD generates no optical beam. 1. A method of ranking a wavelength tunable laser (t-LD) that provides a sampled grating distributed feedback (SG-DFB) region , a chirped sampled grating distributed feedback reflector (CSG-DBR) region , and a semiconductor optical amplifier (SOA) region , the t-LD being mounted on a thermo-electric cooler (TEC) that varies a temperature of the t-LD , the CSG-DBR region providing a heater that varies a temperature of the CSG-DBR region , the t-LD emitting laser light whose wavelength being to be discretely tunable within a wavelength range by setting parameters in the t-LD , the SG-DFB region having an optical gain that shows a maximum in a center of the wavelength range and becomes relatively smaller in peripheries of the wavelength range , the method comprising steps of:driving the t-LD nearby a shortest wavelength and nearby a longest wavelength within the wavelength range by setting parameters that are empirically determined;confirming whether the t-LD generates an optical beam whose wavelength is around the shortest wavelength and the longest wavelength in the wavelength range with and power is around a designed power, degrading a rank of the t-LD, and', 'iterating a step of driving the t-LD at a wavelength next to the shortest ...

SEMICONDUCTOR LASER MODULE

A surface emitting laser element capable of emitting a main beam and a sub-beam, and a monitoring light detection element capable of detecting a light intensity of the sub-beam are included, the surface emitting laser element is a PCSEL, the main beam and the sub-beam are emitted in an upward direction of the surface emitting laser element and are inclined to each other at a predetermined angle, and respective changes in a peak light intensity of the main beam and a peak light intensity of the sub-beam with respect to a value of a driving current of the surface emitting laser element are correlated with each other. Therefore, if an output of the monitoring light detection element indicating the peak light intensity of the sub-beam is used, the peak light intensity of the main beam can be estimated. 1. A semiconductor laser module , comprising:a surface emitting laser element;a monitoring light detection element; anda storage container,wherein the storage container includes an upper wall and a bottom wall,the storage container stores the surface emitting laser element and the monitoring light detection element,the upper wall includes an opening and faces the bottom wall,the surface emitting laser element includes a principal surface, a light emitting region, and a two-dimensional photonic crystal layer, is provided on the bottom wall, emits a main beam and a sub-beam from the light emitting region, and is arranged so that the main beam passes through the opening,the light emitting region is provided on the principal surface,a first optical axis of the main beam extends in a vertical direction of the principal surface,a second optical axis of the sub-beam forms a predetermined angle a with the vertical direction,the two-dimensional photonic crystal layer includes a plurality of hole portions and extends along the principal surface,the plurality of hole portions have a same shape, are arranged in a lattice pattern in a plurality of arrangement directions parallel to ...

Method of evaluating initial parameters and target values for feedback control loop of wavelength tunable system

A method of determining initial parameters and target values for tuning an emission wavelength of a wavelength tunable laser capable of emitting laser light in a substantial wavelength range is disclosed. The method iterates an evaluation of initial parameters and target values at target wavelengths in a preset order. The evaluation includes steps of supplying empirically obtained parameters to the t-LD, confirming whether the t-LD generates an optical beams, determining the initial parameters and the target values by carrying out feedback loops of the AFC and the APC when the t-LD generates the optical beam, or shifting the wavelength range so as to exclude the current target wavelength when the t-LD generates no optical beam.

Systems and Methods for Calibrating, Operating, and Setting a Laser Diode in a Weapon

Systems and methods for calibrating, operating, and setting the magnitude of the power of light provided by a laser diode in a conducted electrical weapon (“CEW”). The light of the laser diode assists in targeting by providing a visible indication of the projected point of impact of the tethered electrode of the CEW. The calibration process enables laser diode of a CEW to operate within regional guidelines of the maximum output power of light permitted by a laser. The method further permits the magnitude of the power of the light provided by a laser diode to be set and operated in changing environmental conditions in the field. 1. A weapon that cooperates with a provided tester , the weapon comprising:a processing circuit;a laser diode; and provide a first signal at a first duty cycle to set an operating point of the laser diode;', 'provide a second signal at a second duty cycle, the second signal turns the laser diode on and off in accordance with the second duty cycle to establish a power of a light provided by the laser diode during a period of the second signal;', 'receive a message from the tester regarding a magnitude of the power as measured by the tester;', 'compare the magnitude of the power to a predetermined range;', 'adjust at least one of the first duty cycle and the second duty cycle responsive to the comparison;', 'repeat receive, compare, and adjust until the magnitude of the power is within the predetermined range., 'a memory having computer-executable instructions stored thereon that, in response to execution by the processing circuit, cause the weapon to2. The weapon of wherein the second duty cycle is about 50 percent.3. The weapon of wherein an active edge of the second signal is synchronous with an active edge of the first signal.4. The weapon of wherein the second signal is generated from the first signal using a divide-by-two counter.5. The weapon of further comprising a photo diode and a resistor coupled to the photo diode claim 1 , wherein: ...

LASER STABILIZING SYSTEM AND LASER SOURCE MODULE

A laser stabilizing system configured to stabilize a laser beam emitted from a laser source includes a beam steering device, a first beam splitter, a first light detector, a second beam splitter, and a second light detector. The beam steering device is configured to steer a direction and a position of the laser beam in four or more degrees of freedom. The first beam splitter is configured to split the laser beam from the beam steering device into a first partial beam and a second partial beam. The first light detector is disposed on a transmission path of the first partial beam. The second beam splitter is configured to split the second partial beam into a third partial beam and a fourth partial beam. The second light detector is disposed on a transmission path of the third partial beam. A laser source module is also provided. 1. A laser stabilizing system configured to stabilize a laser beam emitted from a laser source , the laser stabilizing system comprising:a beam steering device disposed on a path of the laser beam and configured to steer a direction and a position of the laser beam in four or more degrees of freedom;a first beam splitter disposed on a path of the laser beam from the beam steering device and configured to split the laser beam into a first partial beam and a second partial beam;a first light detector disposed on a transmission path of the first partial beam;a second beam splitter disposed on a transmission path of the second partial beam and configured to split the second partial beam into a third partial beam and a fourth partial beam; anda second light detector disposed on a transmission path of the third partial beam.2. The laser stabilizing system according to claim 1 , wherein the beam steering device comprises:a first prism having a first inclined reflecting surface; anda second prism having a second inclined reflecting surface, wherein the laser beam is sequentially reflected by the first inclined reflecting surface and the second ...

LASER SIDE MODE SUPPRESSION RATIO CONTROL

Laser Side Mode Suppression Ratio (SMSR) control is provided via a logic controller configured to measure an SMSR of a carrier wave upstream of a modulator and measure an Average Optical Power (AOP) of the carrier wave downstream of the modulator; transmit a bias voltage based on the SMSR and the AOP to a laser driver for a laser generating the carrier wave; and transmit an attenuation level based on the SMSR and the AOP to a Variable Optical Attenuator (VOA) upstream of the modulator. In various embodiments the attenuation level and bias voltage can rise or fall together, or one may rise and one may fall to ensure the output optical signal meets specified SMSR and AOP values. 1. A system , comprising:a laser;a photodiode;a Side Mode Suppression Ratio (SMSR) sensor optically connected to the laser;a Variable Optical Attenuator (VOA) optically connected to the laser;an optical modulator having an input side connected to the VOA and an output side connected to the photodiode; anda logic controller electrically connected to the laser, the photodiode, the SMSR sensor, and the VOA, configured to adjust a bias of the laser and an attenuation level of the VOA based on an SMSR target, an SMSR reading from the SMSR sensor, and an optical power reading from the photodiode.2. The system of claim 1 , wherein the logic controller is further configured to adjust the bias and the attenuation level to maintain the optical power according to a predefined output power range.3. The system of claim 1 , further comprising:a first tap disposed between the laser and both the SMSR sensor and the VOA that provides a first portion of a beam generated by the laser to the SMSR sensor and a second portion of the beam to the VOA, wherein the second portion includes more optical power than the first portion; anda second tap disposed between the optical modulator and both the photodiode and an output path that provides a third portion of the beam to the photodiode and a fourth portion of the beam ...

LASER POWER CONTROLLER

A laser power controller employs: selection circuitry configured to select one of a data input value, a logical high value or a logical low value such that the selection circuitry selects the data input value during a data transmission period during a defined burst period and selects one of the logical high value and the logical low value during an extension time period during the defined burst period and immediately following the data transmission period; drive circuitry configured to apply, to a laser diode, a current corresponding to the value selected by the selection circuitry during the defined burst period or a zero value otherwise, the current being such that the laser diode is configured to provide an optical output; an optical sensor module configured to provide a sensor module output corresponding to the optical output of the laser diode, and configured to provide an electrical output proportional to the laser diode's optical output corresponding to the logical high value or the logical low value; and a controller configured to receive desired values regarding minimum and maximum optical output power levels of the laser diode and to receive the electrical output from the optical sensor module proportional to the optical output power level corresponding to the logical high and the logical low values; the controller being configured to use the received information to provide control values for the drive circuitry. 1. A system comprising:selection circuitry configured to select one of a data input value, a logical high value or a logical low value such that the selection circuitry selects the data input value during a data transmission period during a defined burst period and selects one of the logical high value and the logical low value during an extension time period during the defined burst period and immediately following the data transmission period;drive circuitry configured to apply a current to a laser diode, the current corresponding to the value ...

Current controlling apparatus for automotive lamp

A current controlling apparatus for an automotive lamp is provided that adjusts a current applied to the automotive lamp that uses laser light as a light source to adjust the intensity of the laser light. The automotive lamp includes a light source that generates laser light and a phosphor excited by the generated laser light to generate light of a predetermined color. A minor is configured to transmit therethrough a first portion of the generated laser light while reflecting a second portion of the generated laser light. A light receiver is configured to receive reflected laser light from the minor and output an output signal based on an intensity of the received laser light. In addition, a controller is configured to detect an intensity of the generated laser light based on the output signal and adjust a current applied to the light source based on results of the detection.

Surface-emitting laser module, optical scanner device, and image forming apparatus

A disclosed surface-emitting laser module includes a surface-emitting laser formed on a substrate to emit light perpendicular to its surface, a package including a recess portion in which the substrate having the surface-emitting laser is arranged, and a transparent substrate arranged to cover the recess portion of the package and the substrate having the surface-emitting laser such that the transparent substrate and the package are connected on a light emitting side of the surface-emitting laser. In the surface-emitting laser module, a high reflectance region and a low reflectance region are formed within a region enclosed by an electrode on an upper part of a mesa of the surface-emitting laser, and the transparent substrate is slanted to the surface of the substrate having the surface-emitting laser in a polarization direction of the light emitted from the surface-emitting laser determined by the high reflectance region and the low reflectance region.

Broadband Tunable External-Cavity Laser Using Small Mems Mirror

A Raman pump laser control apparatus comprises a wavelength division multiplexer, a tap coupler, a photoelectric detector, an analogue amplification processing circuit, an analogue-to-digital converter, a fast Raman pump control unit, an digital-analog converter, and a Raman pump laser. The fast Raman pump control unit, after having known anticipated output light power of the Raman pump laser, based on a direct relationship between a current anticipated output light power of the Raman pump laser and input digital quantity that is needed by the digital-analog converter, uses a feedforward control mechanism so that actual output light power of the Raman pump laser fastly approximates the anticipated output light power thereof, and then synchronously combines with a feedback control mechanism so that the actual output light power of the Raman pump laser is precisely locked on the anticipated output light power, thereby achieving fast and precise control of the Raman pump laser.

Polarization stable widely tunable short cavity laser

A tunable source includes a short-cavity laser optimized for performance and reliability in SSOCT imaging systems, spectroscopic detection systems, and other types of detection and sensing systems. A short cavity laser with a large free spectral range cavity, fast tuning response and single transverse, longitudinal and polarization mode operation is disclosed. Methods for obtaining polarization stable operation of the tunable source are presented.

Noise detection, diagnostics, and control of modelocked lasers

The present invention features a laser based system configured with a noise detection unit. The system includes a mode-locked oscillator. A noise detection unit includes at least one optical detector that monitors optical pulses generated by the mode-locked oscillator and produces an electrical signal in response to the optical pulses. The noise detection unit includes a first filter to transmit signal power over a signal bandwidth which includes the mode-locked laser repetition frequency, frep. The noise detection unit may include one or more filters to transmit power over a noise bandwidth that substantially excludes repetition frequency, frep. Non-linear signal processing equipment is utilized to generate one or more signals representative of the power in the signal bandwidth relative to the power in the noise bandwidth. The system includes a controller operable to generate a signal for controlling the laser based system based on the relative power.

Semiconductor laser driving circuit

The semiconductor laser driving circuit that controls an overshoot on modulation includes a semiconductor laser, of which anode is connected to a power source, that emits the laser light that is modulated by an external modulation input signal, an impedance element connected to a cathode of the laser device, an impedance element connected to the anode, and a collector of a transistor Q1, connected to the impedance element; a collector of a transistor Q2, connected to the other end of the impedance element, a differential pair circuit to which emitters of Q1, Q2 are connected; an electric current source iMOD connected to the emitters of Q1, Q2; and a differential driver that generates a differential voltage (vb1−vb2) that controls Q1, Q2 by driving Q1 by the external modulation input signal, wherein the differential driver controls the differential voltage so that the amplitude of the overshoot of the electric current, which flows in the laser when the output of the laser is at a high-level.

Method and apparatus for coherence enhancement of sweep velocity locked lasers via all-electronic upconversion

The present disclosure provides methods and apparatus to improve the dynamic coherent length of a sweep velocity-locked laser pulse generator (SV-LLPG) in an all-electronic fashion. A digital SV-LLPG is disclosed with two operation modes, i.e., unidirectional and bidirectional sweep modes; self-adaptive and time-dependent loop parameters (gain and location of poles/zeros); and, self-adaptive initial input curve. High frequency locking architectures, both single-side band (SSB) modulation method and direct phase measurement method, are provided to suppress the linewidth, or improve the coherent length, of the swept laser. A combination of high and low frequency locking, or a combination of multiple architectures disclosed in this invention, is utilized to achieve a higher level of linewidth reduction. The enhanced laser coherence extends the measurement range by at least one order of magnitude for applications including frequency-modulated continuous wave (FMCW) light detection and ranging (LiDAR) and optical fiber distributed sensing applications.

LASER WAVELENGTH STABILIZATION APPARATUS

A wavelength sensor for wavelength stabilization of a laser beam includes an etalon placed in the laser beam and tilted with respect to the laser beam. Reflected beams from the etalon form an interference pattern on a segmented photodetector having two detector segments. Output signals from the two detector segments are used to derive an error signal for a closed control loop to effect the wavelength stabilization. 1. A wavelength sensing apparatus for a laser beam comprising:a non-birefringent etalon having first and second parallel surfaces, the etalon located in the laser beam; anda segmented photodetector having first and second detector segments, the etalon being tilted with respect to the laser beam such that first and second reflected beams from respectively the first and second parallel surfaces are directed onto the segmented photodetector to form an interference pattern, the segmented photodetector located at a far-field distance of the first and second reflected beams, the first and second detector segments producing respectively first and second output signals, changes in the first and second output signals corresponding to changes in the wavelength of the laser beam.2. The apparatus of claim 1 , further including a signal processor receiving the first and second output signals claim 1 , and deriving therefrom an error signal that is representative of a phase relationship between the first and second reflected beams.3. The apparatus of claim 2 , wherein the error signal is derived by dividing a difference between the first and second output signals by a total of the first and second output signals.4. The apparatus of claim 3 , wherein the error signal is zero when the first and second reflected beams are completely out-of-phase.5. The apparatus of claim 1 , wherein the laser beam is an output beam of a laser.6. The apparatus of claim 1 , wherein the laser beam is circulating within a laser resonator.7. The apparatus of claim 1 , wherein the interference ...

SYSTEM AND METHOD FOR CONTROLLING COLLOCATED MULTIPLE WAVELENGTH TUNED LASERS

Systems and methods are disclosed herein for controlling laser beams for a plurality of collocated laser assemblies. The laser beams are optimized by controlling outputs of a primary power source (current for generating a laser beam) and a secondary power source (heating device) for each of the respective laser assemblies. The states of the power supply may be cycled and modulated to provide optimal performance. 1detecting at a controller, a plurality of proximal lasers;determining a thermal effect caused by a first of the plurality of lasers on a second of the plurality of proximal lasers; andcontrolling an output of a primary power source.. A method for controlling a plurality of collocated lasers, the method comprising: This application is a continuation of U.S. patent application Ser. No. 14/456,738, filed Aug. 11, 2014, and claims priority to U.S. Provisional Application Ser. No. 61/889,320 filed Oct. 10, 2013, entitled “Semiconductor Laser Thermal Control Method for Collocated Multiple Wavelength Tuned Lasers,” the entire contents of which are hereby incorporated by reference.Semiconductor laser wavelength can vary due to changes in the device temperature. Semiconductor lasers such as distributed feedback (DFB) and/or ridge waveguide lasers often include electronic means to control the intensity and wavelength of the laser by applying a differential voltage to the positive and negative terminal and varying the laser current. By gradually increasing the applied current, the laser will operate with higher optical intensity and increasing wavelength. Only a portion of the applied energy is converted to optical energy while the remaining energy is converted to heat. Various control methods are employed to mitigate thermal variation to maintain desired nominal laser wavelength.One method used to control wavelength in semiconductor lasers is to apply a secondary current to an electrode in proximity to the laser device (e.g., with a heater) to tune the wavelength to ...

ELECTRIC SYSTEM WITH CONTROL WINDING AND METHOD OF ADJUSTING SAME

The invention relates to a method for changing the active number of turns of a control winding () in an electric system (). The control winding is coupled to an AC voltage network for a specified period duration T, is designed for a specified nominal current strength IN, and comprises a first and a second tap (). The control winding is switched from a first continuous current state, in which a load current flows from the first tap to a load discharge line () via a first main path and the second tap is separated from the load discharge line, to a second continuous current state, in which the load current flows from the second tap to the load discharge line via a second main path and the first tap is separated from the load discharge line, according to a specified switch sequence plan. The switch sequence plan specifies that starting from the first continuous current state, the first tap is connected or remains connected to the load discharge line via a first transition path, and the first main path is separated in a switch step a; in a switch step b, the second tap is connected to the load discharge line via a second transition path such that a circuit current iK flows through the transition paths on the basis of the stage voltage between the taps; in a switch step c, the first tap is separated from the load discharge line; and in a switch step d, the second tap is connected to the load discharge line via the second main path; wherein at at least one specified test time tT between switch steps a and c, a test is carried out to determine whether the first main path is separated; a current strength IL of the load current is ascertained; and the test time tT depends on the load current strength IL. 2. The method according to claim 1 , wherein the testing comprises{'b': '1', 'detecting the current i flowing in the first main path and comparing it with a predetermined detection threshold value; and'}evaluating the test result as positive if the threshold value is fallen ...

Laser Driver Modulation and Bias Control Scheme

Systems and methods are provided for generating an accurate, stable measurement for a laser bias current. The average current and the extinction ratio are controlled using a dual control loop. The transfer function between the laser and a monitor photo diode (MPD) is characterized. A laser driver control module predicts the average power that will be measured using the MPD relative to the data being transmitted, and this information is used to control a laser driver.

SINGLE LONGITUDINAL MODE LASER DIODE SYSTEM

A semiconductor laser diode system may include a single longitudinal mode laser diode and a feedback system that monitors and controls the emission characteristics of the laser diode. The laser diode may include a gain medium and an optical feedback device. The feedback system may include a wavelength discriminator, an optical detector, a microprocessor, and a laser controller. Such a semiconductor laser diode system may be used to produce laser light having coherence length, wavelength precision, and wavelength stability that is equivalent to that of a gas laser. Accordingly, such a semiconductor laser diode system may be used in place of a traditional gas laser. 1. A semiconductor laser diode system , comprising:a semiconductor laser source having a laser cavity;an optical feedback device, wherein the optical feedback device is a three-dimensional optical element having a Bragg grating recorded therein, and wherein the Bragg grating causes a narrowband portion of radiation emitted from the laser source to be fed back into the laser cavity, the optical feedback device being configured to cause the laser diode to achieve single longitudinal mode at a desired wavelength; anda feedback system that monitors emission characteristics of the laser diode, the feedback system comprising a processor that is configured to adjust one or more control characteristics of the laser diode to cause the laser diode to achieve and maintain a single longitudinal mode condition using only output power characteristics of the laser diode.2. The semiconductor laser diode system of claim 1 , wherein the Bragg grating causes the narrowband portion of the radiation emitted from the laser source to be fed back into the laser cavity as seed light at the desired wavelength.3. The semiconductor laser diode system of claim 1 , wherein the Bragg grating causes the narrowband portion of the radiation emitted from the laser source to be reflected back into the laser cavity as seed light at the ...

PULSE-WIDTH MODULATION LIGHT SOURCE DRIVE AND METHOD

A pulse-width modulation (PWM) light source drive for driving a light source is provided that includes a microcontroller, a modulation element, a voltage regulator, and a light detector. The microcontroller is configured to generate a PWM signal and an inverse PWM signal. The modulation element is configured to generate a drive signal based on the PWM signal. The light source is configured to be driven by the drive signal. The voltage regulator is configured to generate an output drive voltage for the light source. The light detector is configured to detect light energy emitted by the light source, to generate an optical power feedback signal based on the detected light energy, and to provide the optical power feedback signal to the voltage regulator during a laser-on driving interval. The microcontroller is configured to provide the inverse PWM signal to the voltage regulator during a laser-off driving interval. The voltage regulator is configured to adjust the output drive voltage based on the optical power feedback signal during the laser-on driving interval and based on the inverse PWM signal during the laser-off driving interval. 1. A pulse-width modulation (PWM) light source drive for driving a light source , comprising:a microcontroller configured to generate a PWM signal and an inverse PWM signal;a modulation element configured to generate a drive signal based on the PWM signal, wherein the light source is configured to be driven by the drive signal;a voltage regulator configured to generate an output drive voltage for the light source; anda light detector configured to detect light energy emitted by the light source, to generate an optical power feedback signal based on the detected light energy, and to provide the optical power feedback signal to the voltage regulator during a laser-on driving interval,wherein the microcontroller is further configured to provide the inverse PWM signal to the voltage regulator during a laser-off driving interval, andwherein ...

Method of Estimating a Condition Parameter of a Laser Diode with an Associated Photodiode, Apparatus for Monitoring the Operation of Such Laser Diode and Particular Sensor Apparatus

The present invention provides a method for estimating a condition parameter of a laser diode having an associated photodiode, to an apparatus for monitoring the operation of such a laser diode, and to a particle sensor apparatus. The photodiode (PD) is operable together with the laser diode (LD), wherein it detects the light (LS) of the laser diode (LD) and converts it into an electrical current, and is thermally coupled to the laser diode (LD). The at least one condition parameter is estimated during the operation of the laser diode (LD) and the estimation is based on current measurements and/or voltage measurements at the laser diode (LD) and/or at the photodiode (PD). 2. The method as claimed in claim 1 , wherein the laser diode having the associated photodiode is a laser diode having an integrated photodiode claim 1 , in particular a VCSEL (vertical-cavity surface-emitting laser) having an integrated photodiode.3. The method as claimed in claim 1 , wherein the laser diode temperature TLD is estimated as the condition parameter of the laser diode by way ofdetermining the slope PDSlope of the photodiode characteristic at the laser diode temperature TLD to be determined for at least two different values of the laser diode current ILD using measurements of the photodiode current IPD, andby basing the estimation of the laser diode temperature TLD on a previously determined relationship between the slope PDSlope of the photodiode characteristic and the laser diode temperature TLD.4. The method as claimed in claim 1 , wherein the laser diode temperature TLD is estimated as the condition parameter of the laser diode by way ofcapturing the laser diode voltage ULD for at least one specified laser diode current ILDV at the laser diode temperature TLD that is to be estimated, andbasing the estimation of the laser diode temperature TLD on a previously determined relationship between the predetermined laser diode current ILDV, the laser diode voltage ULD, and the laser diode ...

Optical Transmitter and Light Intensity Monitoring Method

The present invention provides an optical transmitter and a light intensity monitoring method that provide reliable APC feedback for a semiconductor laser equipped with an SOA. The optical transmitter includes an SOA integrated EA-DFB having a DFB laser, an EA modulator connected to the DFB laser, and an SOA connected to the EA modulator. In the structure of the optical transmitter, a light detector part is disposed forward of the output end side of an SOA part. The light detector part changes part of an output light beam from the SOA part into an electric current and detects light, while guiding the remaining part of the output light beam to a waveguide. With the light detector part disposed forward for the SOA part, it is possible to feed back the output result from the SOA part. Hence, good APC is possible. 1. An optical transmitter comprising:an SOA integrated EA-DFB including a DFB laser, an EA modulator connected to the DFB laser, and an SOA connected to the EA modulator;a first light detector for monitoring a signal light beam emitted from the SOA of the SOA integrated EA-DFB; anda drive device connected to the DFB laser and the SOA by a single control terminal, for controlling a drive current in accordance with light intensity detected by the first light detector.2. The optical transmitter according to claim 1 , further comprising a second light detector for monitoring a light beam emitted from the DFB laser claim 1 , the light beam being monitored without passing through the SOA.3. The optical transmitter according to claim 2 , wherein the second light detector is disposed to be connected to an end surface of the DFB laser opposite from an end surface thereof connected to the EA modulator.4. The optical transmitter according to claim 2 , wherein the second light detector is disposed between the DFB laser and the SOA of the SOA integrated EA-DFB.5. (canceled)6. A light intensity monitoring method in an SOA integrated EA-DFB including a DFB laser claim 2 , an ...

Method and Apparatus for Monitoring the Optical Output Power of a Laser Diode with an Associated Photodiode and Particle Sensor Device

The present invention provides methods and an apparatus for monitoring the optical output power of a laser diode (LD) having an associated photodiode (PD), and a particle sensor apparatus. The photodiode (PD) is operable together with the laser diode (LD), wherein it detects the light (LS) of the laser diode (LD) and converts it into an electrical current, and is thermally coupled to the laser diode (LD). Monitoring of the optical output power P is effected during the operation of the laser diode (LD) and is based on current measurements and/or voltage measurements at the laser diode (LD) and at the photodiode (PD). 1. A method for monitoring the optical output power P of at least one laser diode , wherein at least one photodiode is associated with the laser diode ,which is operable together with the laser diode,which detects the light of the laser diode and converts it into an electrical current IPD, andwhich is thermally coupled to the laser diode,wherein the optical output power P is monitored during the operation of the laser diode and the monitoring is based on current measurements and/or voltage measurements at the laser diode and at the photodiode.2. The method as claimed in claim 1 , wherein the laser diode (D) having the associated photodiode is a laser diode having an integrated photodiode claim 1 , in particular a VCSEL (vertical-cavity surface-emitting laser) having an integrated photodiode.3. The method as claimed in claim 1 , whereindetermining a respective instantaneous photodiode characteristic by way of measurements of the photodiode current IPD in dependence on the laser diode current ILD,determining the instantaneous threshold current Ith of the laser diode from the respective instantaneous photodiode characteristic,determining the slope PDSlope of the instantaneous photodiode characteristic for a laser diode current region within which the laser diode is in laser operation, andcapturing the laser diode voltage ULD for at least one specified laser ...

Monitoring a multiplexed laser array in an optical communication system

Individual channels of a multiplexed laser array in a multi-channel optical transmitter are monitored at an output of an optical multiplexer. The monitoring may be used to confirm proper operation of each of the channels in the multiplexed laser array and/or to perform wavelength locking on each of the channels. Monitoring at the output of the optical multiplexer avoids the use of multiple photodetectors coupled directly to multiple lasers in the multiplexed laser array. The multiplexed laser array generally includes a plurality of laser emitters optically coupled to an optical multiplexer such as an arrayed waveguide grating (AWG). An optical transmitter with a monitored multiplexed laser array may be used, for example, in an optical line terminal (OLT) in a wavelength division multiplexed (WDM) passive optical network (PON) or in any other type of WDM optical communication system capable of transmitting optical signals on multiple channel wavelengths.

BROADBAND ARBITRARY WAVELENGTH MULTICHANNEL LASER SOURCE

A multi-channel laser source, including: a bus waveguide coupled, at an output end of the bus waveguide, to an output of the multi-channel laser source; a first semiconductor optical amplifier; a first back mirror; a first wavelength-dependent coupler, having a first resonant wavelength, on the bus waveguide; a second semiconductor optical amplifier; a second back mirror; and a second wavelength-dependent coupler, on the bus waveguide, having a second resonant wavelength, different from the first resonant wavelength. In some embodiments the first semiconductor optical amplifier is coupled to the bus waveguide by the first wavelength-dependent coupler, which is nearer to the output end of the bus waveguide than the second wavelength-dependent coupler, the second semiconductor optical amplifier is coupled to the bus waveguide by the second wavelength-dependent coupler, and the first wavelength-dependent coupler is configured to transmit light, at the second resonant wavelength, along the bus waveguide. 1. A multi-channel laser source , comprising:a bus waveguide coupled, at an output end of the bus waveguide, to an output of the multi-channel laser source;a first semiconductor optical amplifier;a first back mirror;a first wavelength-dependent coupler having a first resonant wavelength;a second semiconductor optical amplifier;a second back mirror; anda second wavelength-dependent coupler having a second resonant wavelength, different from the first resonant wavelength;{'claim-text': ['a first end coupled to the first back mirror, and', 'a second end,'], '#text': 'the first semiconductor optical amplifier comprising:'}{'claim-text': ['a channel port connected to the second end of the first semiconductor optical amplifier;', 'a bus output connected to a first portion of the bus waveguide; and', 'a bus input, connected to a second portion of the bus waveguide more distant from the output end of the bus waveguide than the first portion of the bus waveguide;'], '#text': ' ...

REPEATER, EXCITATION LIGHT SUPPLY DEVICE USED FOR THE SAME, AND EXCITATION LIGHT SUPPLY METHOD

Even when some light emitting elements among the plurality of light emitting elements fail, a repeater, can be continuously operated. Means for solving the problems A light source unit which includes a plurality of pumping light source modules (to ) which include light emitting elements (to ) for emitting an excitation light and monitor elements (to ) for monitoring the excitation lights of the light emitting elements (to ), respectively, a distribution unit which combines the excitation lights from the plurality of pumping light source modules (to ) and distributes it, and a control unit which supplies a drive current flowing serially through the plurality of light emitting elements (to ) in a plurality of excitation modules (to ) are included. 1. An excitation light supply device which supplies an excitation light , comprising:a light source unit which includes a plurality of excitation light source modules, each of which includes a light emitting element for emitting the excitation light and a monitor element for monitoring the excitation light of the light emitting element;a distribution unit which combines the excitation lights from the plurality of excitation light source modules and distributes the combined excitation lights; anda control unit which supplies a drive current flowing serially through the plurality of light emitting elements in a plurality of excitation modules.2. The excitation light supply device according to claim 1 , whereinthe control unit comprises:a control circuit which detects an output signal of the monitor element, obtains a sum of the output signals as a monitor signal, generates a drive signal by which a level of the monitor signal is made equal to a reference value set in advance and outputs the drive signal; anda drive circuit which outputs the drive current to the light source unit based on the drive signal.3. The excitation light supply device according to claim 2 , whereinthe control circuit monitors whether or not a no signal ...

LASER LIGHT SOURCE DEVICE AND METHOD OF CONTROLLING SAME

An object is to provide a technology capable of suppressing life deterioration of a laser light source device. A laser light source device includes a laser bank having a plurality of semiconductor laser elements, a drive part for applying an electric current to the plurality of semiconductor laser elements of the laser bank, a light intensity detection part for detecting light intensity output from the laser bank, a temperature detection part for detecting a temperature of the laser bank, and a control part for determining an electric current limit value based on the detected temperature, and for controlling the electric current of the drive part based on the detected light intensity and the electric current limit value. 1. A laser light source device comprising:a laser bank having a plurality of semiconductor laser elements;a drive part for applying an electric current to the plurality of semiconductor laser elements of the laser bank;a light intensity detection part for detecting light intensity output from the laser bank;a temperature detection part for detecting a temperature of the laser bank; anda control part for determining an electric current limit value being a limit value of the electric current of the drive part based on the temperature detected by the temperature detection part, and for controlling the electric current of the drive part based on the light intensity detected by the light intensity detection part and the electric current limit value, whereina first temperature range and a second temperature range that is higher than the first temperature range are defined for the temperature of the laser bank, andthe electric current limit value comprises an electric current upper limit value for preventing COD deterioration of the plurality of semiconductor laser elements in the first temperature range, and an electric current upper limit value for preventing COD deterioration and gentle thermal deterioration of the plurality of semiconductor laser ...

RANDOM NUMBER SEQUENCE GENERATION APPARATUS, QUANTUM ENCRYPTION TRANSMITTER, AND QUANTUM ENCRYPTION COMMUNICATION SYSTEM

A random number sequence generation apparatus includes: a semiconductor laser device repeatedly generating a pulsed laser beam having a disordered phase; an interferometer including a first transmission line and a second transmission line, a first port connected to an input terminal side and to which the pulsed laser beam is input, a second port connected to an output terminal side and outputs the pulsed laser beam, and a third port connected to the input terminal side; a Faraday mirror connected to the second port and reflecting the pulsed laser beam; a photodiode connected to the third port and outputs an electrical signal in accordance with interference light of the pulsed laser beam that is reflected by the Faraday mirror and passes through one of the transmission lines; and an AD converter configured to generate a random number sequence on the basis of the electrical signal and a threshold. 1. A random number sequence generation apparatus comprising:a semiconductor laser device repeatedly generating a pulsed laser beam having a disordered phase for each pulse through pulse oscillation;an interferometer including a first transmission line and a second transmission line that have mutually-different transmission line lengths, a first port connected to an input terminal side of the first transmission line and the second transmission line and to which the pulsed laser beam is input, a second port that is connected to an output terminal side of the first transmission line and the second transmission line and outputs the pulsed laser beam that is input to the first port and passes through the first transmission line or the second transmission line, and a third port that is connected to the input terminal side;a Faraday mirror connected to the second port and inputting the pulsed laser beam output from the second port to the second port again by reflecting the pulsed laser beam;a photodiode connected to the third port, to which interference light of the pulsed laser ...

METHOD TO TUNE EMISSION WAVELENGTH OF WAVELENGTH TUNABLE LASER APPARATUS AND LASER APPARATUS

A method to tune an emission wavelength of a wavelength tunable laser apparatus is disclosed. The laser apparatus implements, in addition to a wavelength tunable laser diode (t-LD) integrating with a semiconductor optical amplifier (SOA), a wavelength monitor including an etalon filter. The current emission wavelength is determined by a ratio of the magnitude of a filtered beam passing the etalon filter to a raw beam not passing the etalon filter. The method first sets the SOA in an absorbing mode to sense stray component disturbing the wavelength monitor, then correct the ratio of the beams by subtracting the contribution from the stray component. 1. A method to tune an emission wavelength of a laser apparatus that includes a wavelength tunable laser diode (t-LD) integrating a laser diode (LD) with a semiconductor optical amplifier (SOA) , and a wavelength monitor to sense the emission wavelength of the t-LD , the wavelength monitor disposed in one of a front side and a rear side of the t-LD , the wavelength monitor including an optical filter , a first photodiode (PD) to sense a raw beam not transmitting through the optical filter , and a second PD to sense a filtered beam split from the raw beam and transmitting through the optical filter , the method comprising steps of:evaluating a first stray component and a second stray component by the first PD and the second PD, respectively, the first stray component and the second stray component originating to an optical beam output from another of the front side and the rear side not disposing the wavelength monitor;sensing the raw beam and the filtered beam by the first PD and the second PD, respectively; andcalculating a ratio of the filtered beam subtracted with the second stray component to the raw beam subtracted with the first stray component,wherein the SOA is integrated in the front side of the t-LD and the wavelength monitor is disposed in the front side of the t-LD, and setting the SOA in an absorbing mode;', ...

TRANSISTOR OUTLINE HEADER FOR HIGH-SPEED DATA TRANSMISSION OF OPTOELECTRONIC APPLICATIONS

A header for opto-electronic applications is provided. The header includes a header base with a back face, a front face, and opening that extends from the back face through the base to the front face. The opening accommodates an electrically isolated pin through the opening. A pedestal is arranged at the front face and is below a center of the opening. The pedestal has a mounting face and a free face, which opposes the mounting face. The pedestal further includes an upper surface for mounting and carrying a pedestal submount. The mounting face is fixedly attached to the front face with an electrically conductive material that is at least partially arranged between the front face and the mounting face. An electrically isolating material is arranged in the opening between the base and the pin to electrically isolate the pin from the base.

Driver circuitry and systems for high current laser diode arrays

Apparatuses, methods, and systems are disclosed to drive pumping laser diode arrays. In implementations, an integrated system can be constructed to in a compact, efficient and cost-effective manner and to meet the needs of driving laser diode arrays in various diode pumped solid state laser applications. The disclosed implementations include individual laser diode drivers or pulsers, methods of communicating with laser diode drivers, and methods of controlling the pulse shape of each laser diode driver.

LASER APPARATUS AND RESERVOIR COMPUTING SYSTEM

To realize a reservoir computing system with a small size and reduced learning cost, provided is a laser apparatus including a laser; a feedback waveguide that is operable to feed light output from the laser back to the laser; an optical splitter that is provided in a path of the feedback waveguide and is operable to output a portion of light propagated in the feedback waveguide to outside; and a first ring resonator that is operable to be optically connected to the feedback waveguide, as well as a reservoir computing system including this laser apparatus. 1. A reservoir computing system comprising: a laser,', 'a feedback waveguide that is operable to feed light output from the laser back to the laser,', 'an optical splitter that is provided in a path of the feedback waveguide and is operable to output a portion of light propagated in the feedback waveguide to outside the feedback waveguide, and', 'a first ring resonator that is operable to be optically connected to the feedback waveguide;, 'a reservoir including a laser apparatus, wherein the laser apparatus includes'}an input node operable to supply the reservoir with an input signal corresponding to input data;an output node operable to output an output value corresponding to light output by the reservoir in response to the input data; andan output section operable to output output data corresponding to the output value.2. The reservoir computing system according to claim 1 , whereinthe laser apparatus further includes one or more second ring resonators, andeach of the one or more second ring resonators is operable to be optically connected to the first ring resonator directly or indirectly via another of the second ring resonators.3. The reservoir computing system according to claim 2 , whereina plurality of the second ring resonators are operable to be optically connected in series, andthe second ring resonator positioned at a first end among the plurality of second ring resonators is operable to be optically ...

Laser assembly that provides an adjusted output beam having symmetrical beam parameters

A laser assembly ( 10 ) for providing a beam ( 20 ) includes a gain chip ( 12 ) and an axisymmetric optical assembly ( 16 ). The gain chip ( 12 ) emits an astigmatic, output beam ( 14 ). The optical assembly ( 16 ) adjusts the output beam ( 14 ) so that an adjusted output beam ( 20 ) has an adjusted first axis divergence angle and an adjusted second axis divergence angle. In certain embodiments, a magnitude of the adjusted first axis divergence angle is approximately equal to a magnitude of an adjusted second axis divergence angle in the far field.

OPTIMIZATION OF THE LASER OPERATING POINT IN A LASER ABSORPTION SPECTROMETER

An operating value of a first laser parameter of a laser device in a laser absorption spectrometer is optimized. The wavelength of laser device emitted light is adjusted by the first or a second laser parameter. The laser absorption spectrometer comprises a light intensity detector measuring the laser light intensity from the laser device. For each of multiple values of the first laser parameter: the light intensity detector measures light intensity obtained across a range of second laser parameter values, and an extremum in the light intensity measure and a peak position for the extremum are identified. A range of first laser parameter values is identified within the values of the first laser parameter for which there is a continuous trend in changes to the identified peak position with changes to the first laser parameter. The first laser parameter operating value is set to be within the identified range. 1. A method for optimizing an operating value of a first laser parameter of a laser device in a laser absorption spectrometer , wherein the wavelength of laser light emitted from the laser device is variable by adjusting either of the first laser parameter and a second laser parameter of the laser device , and wherein the laser absorption spectrometer includes a light intensity detector configured to measure the intensity of laser light received from the laser device , the method comprising: obtaining a measure of light intensity received at the light intensity detector across a range of values of the second laser parameter;', 'identifying an extremum in the measure of light intensity; and', 'identifying a peak position for the extremum;, 'for each of a plurality of values of the first laser parameteridentifying a range of values of the first laser parameter within the plurality of values of the first laser parameter for which there is a continuous trend in changes to the identified peak position with changes to the first laser parameter; andsetting the operating ...

LIGHT SOURCE DRIVING APPARATUS AND IMAGE DISPLAY APPARATUS

A light source emits a laser light. A driver drives the light source based on a driving signal constituted by a pulse that changes a driving current value. When a luminance corresponding to a first laser output power that exceeds a threshold value is to be expressed, a controller controls the driver to supply to the light source a pulse having a first duty cycle at a first driving current value corresponding to the first laser output power. When a luminance corresponding to a second laser output power that is equal to or less than the threshold value is to be expressed, the controller controls the driver to supply to the light source a pulse having a second duty cycle that is smaller than the first duty cycle at a second driving current value corresponding to a third laser output power that exceeds the threshold value. 1. A light source driving apparatus comprising:a light source constituted by a semiconductor laser that emits a laser light;a driver configured to drive the light source based on a driving signal constituted by a pulse having a predetermined duty cycle that changes a driving current value; anda controller configured to control the driver, when a luminance corresponding to a first laser output power exceeding a threshold value, which is a predetermined laser output power, is to be expressed by the laser light that is output by the light source, is configured to control the driver to supply to the light source a driving signal constituted by a pulse having a first duty cycle at a first driving current value corresponding to the first laser output power such that the light source emits a laser light having the first laser output power,', 'when a luminance corresponding to a second laser output power that is equal to or less than the threshold value is to be expressed by the laser light that is output by the light source, is configured to control the driver to supply to the light source a driving signal constituted by a pulse having a second duty cycle ...

Packaging structure and method of packaging tunable laser device, and tunable laser device

The present disclosure provides a packaging structure and a method of packaging an tunable laser device, and an tunable laser device. The packaging structure of the tunable laser device may include a TO tube base and a TO tube cap, wherein a first thermal sink is disposed on the TO tube base, a semiconductor laser chip is disposed on a vertical side of the first thermal sink, an aspheric lens is disposed on the TO tube cap, and the semiconductor laser chip is disposed on a central axis of the aspheric lens; and wherein the vertical side of the first thermal sink is a side of the first thermal sink perpendicular to the TO tube base. The tunable laser device according to the present disclosure may be applicable to communication over an optical fiber.

LIGHT EMISSION MODULE

A light emission module includes a base, a laser diode driver, a laser diode and a monitor photodiode. The laser diode driver, the laser diode and the monitor photodiode are disposed on the base. The monitor photodiode and the laser diode are located close to a front end of the laser diode driver. A rear side of the laser diode facing the front end of the laser diode driver. A end surface at the front end of the laser diode driver, a side surface at the rear side of the laser diode and a light receiving surface of the monitor photodiode are arranged in a triangle shape for reflecting a light emitted from the rear side of the laser diode to the light receiving surface of the monitor photodiode by the end surface of the laser diode driver. 1. A light emission module comprising a base , a laser diode driver , a laser diode and a monitor photodiode , the laser diode driver , the laser diode and the monitor photodiode disposed on the base , the monitor photodiode and the laser diode located close to a front end of the laser diode driver , a rear side of the laser diode facing the front end of the laser diode driver , the laser diode driver having an end surface located at the front end , the laser diode having a side surface located the rear side , and the monitor photodiode having a light receiving surface; the end surface of the laser diode driver , the side surface of the laser diode and the light receiving surface of the monitor photodiode arranged in a triangle shape for reflecting a light emitted from the rear side of the laser diode to the light receiving surface of the monitor photodiode by the end surface of the laser diode driver.2. The light emission module of claim 1 , wherein an angle between the end surface of the laser diode driver and an emission axis of the laser diode is from 20 degrees to 60 degrees.3. The light emission module of claim 2 , wherein the angle between the end surface of the laser diode driver and an emission axis of the laser diode is ...

METHOD AND APPARATUS FOR MATCHING IMPEDANCE OF OPTICAL COMPONENTS USING A TAPERED TRANSMISSION LINE

A method and apparatus for matching different impedance of optical components and a package for optical communication using a tapered transmission line (or a taper) are provided. The taper may be configured to include a first section, a second section, and a third section, each of which corresponds to different components. By way of example, the first section of the taper may be configured to be allocated to a driver to a flex joint on a printed circuit board (PCB), the second section of the taper may be configured to be allocated to a flex circuit, and the third section of the taper may be configured to be allocated to a transistor outline (TO) and submount including a directly modulated laser (DML). The taper is configured to minimize an amount of impedance mismatch between the optical components and the package. 1. A method of matching impedance of a directly modulated laser (DML) using a taper , wherein the taper is configured to include a first section , a second section , and a third section , and wherein the first section of the taper is configured to be allocated to a driver to a flex joint on a printed circuit board (PCB) or a printed wire board (PWB) , the second section of the taper is configured to allocated to a flex circuit , and the third section of the taper is configured to be allocated to a package and submount including the DML.2. The method of claim 1 , wherein the DML is enclosed in a package and wherein the package comprises a transistor outline (TO) claim 1 , a ceramic box claim 1 , a Consortium on board optics (COBO) claim 1 , or a chip on board (COB) package.3. The method of claim 1 , wherein the first section of the taper comprises first three segments claim 1 , the second section of the taper comprises second fifteen segments claim 1 , and the third section of the taper comprises third three segments.4. The method of claim 4 , wherein the first section of the taper and the third section of the taper are relatively short and an impedance ...

Light source apparatus, light source driving method, and observation apparatus

A light source apparatus according to an embodiment of the present technology includes a white light source, a plurality of laser light sources, a detection unit, and a light source control unit. The white light source emits white light. The plurality of laser light sources emit a plurality of laser lights capable of adjusting a color temperature of the white light. The detection unit is capable of detecting a failure of each of the white light source and the plurality of laser light sources. The light source control unit controls an intensity ratio of the plurality of laser lights that are emitted from the plurality of laser light sources in a case where the failure of the white light source is detected.

Coherent Optical Distance Measurement Apparatus and Method

This disclosure presents a non-contact, frequency modulated continuous wave (FMCW) coherent optical distance measuring system and method for determining a measured distance over a wide distance range and simultaneously with fine range resolution. The approach and apparatus presented within eliminates the need for expensive, high frequency post-detection electronics to perform the necessary signal processing to accurately determine distance. 1. A distance measuring apparatus , comprising:{'sub': 1', '1', '1, 'a first laser diode with a first frequency chirp dFand first chirp rate (dF/Tp);'}{'sub': 2', '2', '2, 'a second laser diode with a second frequency chirp dFand second chirp rate (dF/Tp);'}a planar lightwave circuit including a pair of photodetectors, a combiner optomechanically connected to a cascaded pair of 3 dB directional couplers, a gradient index rod lens, and a partially reflectiveFaraday mirror optomechanically coupled to the gradient index rod lens, wherein the first laser diode is optically coupled to a first input port of the combiner, the second laser diode is optically coupled to a second input port of the combiner, a first output port of the combiner is optically coupled to a first input port of a first 3 dB directional coupler, a first output port of the first directional coupler is optomechanically coupled to the gradient index rod lens, the second input port of the first directional coupler is optomechanically connected to a first input port of a second directional coupler, and the two output ports of the second directional coupler are each optomechanically coupled to a photodetector;further comprising a third laser diode optomechanically coupled to a first input port of a second combiner on the planar lightwave circuit, and a fourth laser diode optomechanically coupled to a second input port of the second combiner, a third photodetector coupled to a first output port of the second combiner, and a fourth photodetector optomechanically coupled ...

Light-emitting element module, atomic oscillator, and electronic apparatus

A light-emitting element module includes a light-emitting element that emits light, a base that has a depression portion in which the light-emitting element is accommodated, and a lid that covers an opening of the depression portion and is joined to the base. The lid includes a protrusion portion that protrudes on an opposite side to the base and has a hole through which the light passes and a window that is installed in the protrusion portion to block the hole and transmits the light. A surface of the window on a side of the light-emitting element is inclined with respect to a surface perpendicular to an optical axis of the light.

Iii-v lasers with on-chip integration

Structures for integrated lasers, systems including integrated lasers, and associated fabrication methods. A ring waveguide and a seed region are arranged interior of the ring waveguide. A laser strip extends across a portion of the ring waveguide. The laser strip has an end contacting the seed region and another opposing end. The laser strip includes a laser medium and a p-n junction capable of generating electromagnetic radiation. The p-n junction of the laser strip is aligned with a portion of the ring waveguide.

LONG-LIFE, HIGH-EFFICIENCY LASER APPARATUS HAVING PLURALITY OF LASER DIODE MODULES

A laser apparatus includes laser diode module groups (LDMGs) and power supply units and provides a laser light source by collecting laser beam from the LDMGs, and comprises: a driving current supply circuit network for injecting the driving currents into the respective LDMGs, independently; a control unit which controls the driving currents independently; a first recording unit in which are recorded data representing a relationship between the driving current and optical output power, and data representing a relationship between the driving current and drive voltage; and a first calculating unit which calculates the driving currents to be allocated to the LDMGs so as to achieve maximum electrical to optical conversion efficiency, wherein the control unit allocates the driving currents to the LDMGs in accordance with the results calculated by the first calculating unit so that the LDMGs as a whole can achieve maximum electrical to optical conversion efficiency under conditions. 1. A laser apparatus which includes a plurality of laser diode module groups each containing at least one laser diode module , and a plurality of power supply units each for supplying a driving current to a corresponding one of the plurality of laser diode module groups , and which provides a laser light source or a pumping light source for laser oscillation by collecting laser beam from the plurality of laser diode module groups , the laser apparatus comprising:a driving current supply circuit network which is capable of injecting the driving currents from the plurality of power supply units into the plurality of respective laser diode module groups, independently for each of the plurality of laser diode module groups;a control unit which controls the driving currents to be injected from the plurality of power supply units into the plurality of respective laser diode module groups, independently for each of the plurality of laser diode module groups;a first recording unit in which are ...

METHOD FOR OUTPUTTING NETWORKING AUTHENTICATION INFORMATION, NETWORKING METHOD, APPARATUS AND STORAGE MEDIUM

The present disclosure relates to a method for outputting networking authentication information, a networking method, an apparatus and a storage medium. The method includes: obtaining networking authentication information; determining, based on a preset rule, a light emission control signal corresponding to the networking authentication information; and controlling, based on the light emission control signal, the first terminal to output an optical signal corresponding to the networking authentication information. 1. A method for outputting networking authentication information , applied to a first terminal , the method comprising:obtaining networking authentication information;determining, based on a preset rule, a light emission control signal corresponding to the networking authentication information; andcontrolling, based on the light emission control signal, the first terminal to output an optical signal corresponding to the networking authentication formation.2. The method according to claim 1 , wherein the controlling the first terminal to output the optical signal corresponding to the networking authentication information comprises:controlling at least one of a screen or a flash of the first terminal to flicker to output the optical signal.3. The method according to claim 1 , wherein the determining claim 1 , based on the preset rule claim 1 , the light emission control signal corresponding to die networking authentication information comprises:converting a character in the networking authentication information into a corresponding light emission control signal by at least one of a Morse code rule or an American Standard Code for Information Interchange (ASCII) rule.4. The method according to claim 1 , wherein the networking authentication information comprises at least one of:a networking password; a networking service set identifier; or a running parameter.5. A networking method claim 1 , applied to a second terminal claim 1 , the method comprising: ...

Laser system for Generating Single-Sideband Modulated Laser Radiation

The invention relates to a laser system comprising a laser light source () that emits laser radiation during operation of the laser system, a modulation means () that brings about modulation of the laser radiation emitted by the laser light source () such that the spectrum of the laser radiation comprises a carrier () and two sidebands () that are symmetrically distributed around the carrier, and at least one optical amplifier () that amplifies the radiation emitted by the laser light source (). The invention proposes that an optical filter () be provided in the beam path of the laser radiation, upstream of the optical amplifier (), which filter is intended for removing the spectral portion of the laser radiation at the frequency of one of the two sidebands (). The laser system is suitable inter alia for generating an artificial guide star (“laser guide star”) for astronomical telescopes comprising adaptive optics. The invention furthermore relates to a method for generating single-sideband modulated laser radiation. 1. Laser system , comprisinga laser light source that is configured to emit laser radiation during operation of the laser system,a modulation means that is configured for modulating the emitted laser radiation such that the frequency spectrum of the laser radiation comprises a carrier and two sidebands that are symmetrically distributed around the carrier, andat least one optical amplifier that is configured for amplifying the laser radiation,wherein an optical filter is arranged in the beam path of the laser radiation, upstream of the optical amplifier, which filter is configured to remove the spectral portion of the laser radiation at the frequency of one of the two sidebands.2. Laser system according to claim 1 , wherein the optical filter is an optical notch filter.3. Laser system according to claim 1 , wherein the optical filter is a fiber-Bragg grating claim 1 , in particular a π-phase-shifted fiber-Bragg grating claim 1 , which grating transmits ...

DEVICE PACKAGE AND METHODS FOR THE FABRICATION AND TESTING THEREOF

Method of making an optoelectronic device package. 1. A method of making an optoelectronic device package , comprising:providing a base substrate comprising an optoelectronic device mounting region on a surface of the base substrate and a lid mounting region;forming a fiber groove in the base substrate disposed along an optical axis at a location external to the lid mounting region;bonding an optoelectronic device to the optoelectronic device mounting region;mounting a lid on the lid mounting region to form an enclosed volume between the base substrate and the lid, wherein the optoelectronic device is in the enclosed volume, wherein at least a portion of the lid mounting region is disposed along the optical path below the surface of the base substrate to a depth below the optical path;providing an optical fiber segment in the fiber groove; andplacing an encapsulant over the optical element and/or the fiber segment.2. The method of claim 1 , wherein the lid comprises silicon.3. The method of claim 1 , comprising oxidizing a sidewall portion of a silicon lid through its depth to provide an optically transmissive silicon dioxide sidewall region. This application is a continuation of U.S. patent application Ser. No. 15/584,542, filed May 2, 2017, which issued as U.S. Pat. No. 9,817,199 on Nov. 13, 2017, which is a continuation of U.S. patent application Ser. No. 15/230,944, filed Aug. 8, 2016, which issued as U.S. Pat. No. 9,647,420 on May 9, 2017, which is a continuation of U.S. patent application Ser. No. 14/657,131, filed Mar. 13, 2015, which issued as U.S. Pat. No. 9,410,799 on Aug. 9, 2016, which is a continuation of U.S. patent application Ser. No. 14/258,358, filed Apr. 22, 2014, which issued as U.S. Pat. No. 8,993,450 on Mar. 31, 2015, which is a continuation of U.S. patent application Ser. No. 12/944,040, filed Nov. 11, 2010, which issued as U.S. Pat. No. 8,703,603 on Apr. 22, 2014, which is a continuation of U.S. patent application Ser. No. 11/590,099, filed ...

METHOD FOR REDUCING SELF-MIXING INTERFERENCE EFFECT OF LASER SYSTEM

The present invention discloses a method for reducing a self-mixing interference effect of a laser system, comprising the following step: connecting a direct current (DC) bias circuit and a modulated signal generator to electrodes of a laser, respectively. The DC bias circuit is configured to drive the laser and provide carriers for pumping to the laser; a resonant cavity is provided in the laser, and is configured to convert the carriers for pumping into photons which are subjected to stimulated radiation to form stable laser output; the DC bias circuit and the modulated signal generator are injected into the laser; the modulated signal generator outputs a modulated signal; and the modulated signal matches a parasitic parameter of the laser so as to change the distribution state of the photons in the resonant cavity of the laser. The present invention spatially and temporally reduces power fluctuation of a laser within a short period of time caused by the self-mixing interference effect, ensures the stability of the whole laser system, and has the advantages of low cost, easy assembly and adjustment, and stable performance. 22311. The method for reducing a self-mixing interference effect of a laser system according to claim 1 , wherein the parasitic parameter is a parasitic capacitance or a parasitic resistance; the DC bias circuit () and the modulated signal generator () are injected into the laser (); the modulated signal claim 1 , the parasitic capacitance claim 1 , and the parasitic resistance constitute a resonance relationship which is embodied as a chirp effect in terms of optical output; resonant cavity laser output modes are increased claim 1 , after a trace amount of returned light is applied to the laser claim 1 , the influence of the self-mixing interference effect in multiple modes on the laser is less than that of equivalent self-mixing interference effect in a single mode or a few modes claim 1 , and then the laser () outputs stable laser beams. ...

EXTERNAL CAVITY LASER WITH A PHASE SHIFTER

Systems and methods described herein are directed to optical light sources, such as an external cavity laser (ECL) with an active phase shifter. The system may include control circuity for controlling one or more parameters associated with the active phase shifter. The phase shifter may be a p-i-n phase shifter. The control circuitry may cause variation in a refractive index associated with the phase shifter, thereby varying a lasing frequency of the ECL. The ECL may be configured to operate as a light source for a light detection and ranging (LIDAR) system based on generating frequency modulated light signals. In some embodiments, the ECL may generate an output LIDAR signal with alternating segments of increasing and decreasing chirp frequencies. The ECL may exhibit increased stability and improved chirp linearities with less dependence on ambient temperature fluctuations. 1. A method for chirping a laser output wavelength , comprising:controlling, by a computing device, a laser drive current;selecting, by the computing device and based on the laser drive current, an initial voltage bias associated with a phase shifter element;analyzing, by the computing device, a chirp linearity associated with the laser output wavelength; andvarying, by the computing device and based on the chirp linearity, the initial voltage bias associated with the phase shifter element.2. The method of claim 1 , wherein the varying the initial voltage bias is based on:determining a linearity correction factor associated with the chirp linearity; andapplying the linearity correction factor to a waveform of the initial voltage bias.3. The method of claim 1 , further comprising:periodically monitoring the chirp linearity associated with the laser output wavelength;determining that the chirp linearity has satisfied a threshold linearity value;determining a modified voltage bias waveform based on the threshold linearity value; andapplying the modified voltage bias waveform to the phase shifter ...

VIDEO DISPLAY DEVICE

A video display device includes a laser beam source module including a laser beam source emitting a laser beam and a laser beam source drive unit supplying power to the laser beam source, and an image generation unit generating a desired display image from the laser beam. The laser beam source module includes a substrate having the placed laser beam source and improved thermal conductivity, a temperature measurement member measuring a temperature of the substrate, a temperature adjustment member contacting the substrate and adjusting the temperature of the substrate, a circuit substrate electrically connecting the temperature measurement member and the laser beam source. Moreover, the circuit substrate is disposed on a rear surface opposite to a placement surface on which the laser beam source is placed, the temperature measurement member is mounted on the circuit substrate, and a portion of the temperature measurement member is connected to the substrate. 1. A video display device allowing an observer to observe video of a display image , comprising:a laser beam source module including a laser beam source emitting a laser beam and a laser beam source drive unit that supplies power to the laser beam source; andan image generation unit that generates a desired display image from the laser beam,wherein the laser beam source module includes:a substrate on which the laser beam source is placed and which has improved thermal conductivity;a temperature measurement member that measures a temperature of the substrate;a temperature adjustment member that contacts the substrate and adjusting the temperature of the substrate; anda circuit substrate that electrically connects the temperature measurement member and the laser beam source,wherein the circuit substrate is disposed on a rear surface opposite to a placement surface on which the laser beam source is placed,wherein the temperature measurement member is mounted on the circuit substrate, andwherein a portion of the ...

TUNABLE LASER WITH DIRECTIONAL COUPLER

A tunable laser has a first mirror, a second mirror, a gain medium, and a directional coupler. The first mirror and the second mirror form an optical resonator. The gain medium and the directional coupler are, at least partially, in an optical path of the optical resonator. The first mirror and the second mirror comprise binary super gratings. Both the first mirror and the second mirror have high reflectivity. The directional coupler provides an output coupler for the tunable laser. 1. (canceled)2. A device for a laser comprising:a first mirror having a first plurality of reflectance peaks;a second mirror having a second plurality of reflectance peaks, wherein the first mirror and the second mirror are configured to form a resonator;a gain medium within the resonator; anda coupler between the first mirror and the second mirror, the coupler configured to guide a selected percentage of light directly, not evanescently, out of the resonator through a port of the coupler, such that the selected percentage of light coupled out of the resonator is independent of spectral properties of the first mirror and the second mirror, and wherein the coupler is a waveguide coupler.3. The device of claim 2 , wherein:wherein a maximum reflectance of the first plurality of reflectance peaks is greater than 90%; andwherein a maximum reflectance of the second plurality of reflectance peaks is greater than 90%.4. The device of claim 2 , wherein:the coupler comprises a ridge portion having a width at a waist of the coupler, wherein the waist is at a center of the coupler; andthe selected percentage of light guided out of the resonator through the port of the coupler is based on the width of the ridge portion at the waist of the coupler.5. The device of claim 2 , wherein:the coupler comprises a first ridge and a second ridge;a gap separates the first ridge from the second ridge; andthe gap is equal to or greater than 0.75 microns.6. The device of claim 2 , wherein the first mirror claim 2 , ...

Dual-Rate DML Device And Module Having Built-In Signal Calibration Circuit, And Signal Calibration Method

The present invention relates to a technical field of optical communications. It relates to a dual-rate DML device and module, and a calibration method, and in particular, to a dual-rate DML device and module having a built-in signal calibration circuit, and a calibration method. According to the present invention, the signal calibration circuit is added into the device; a PD is prepositioned by means of a novel light splitting structure; a control structure for a sequence-divided multi-channel serial signal is utilized to feed back a monitoring signal to an electric driver to adjust drive current; crosstalk between backlight monitoring is reduced; and high-quality signal output under dual modulation frequencies of 25 Gbps and 28 Gbps is realized.

Photodetection device, photodetection method, and optical transmission device

The light reception unit is disposed behind each of a plurality of light sources that emits signal lights having mutually different wavelengths in a forward direction and receives a backlight emitted backward from each of the light sources. The synchronizing signal generation unit generates a synchronizing signal serving as an electric signal synchronized in phase with a drive signal for driving each of the light sources. The multiplication unit multiplies the synchronizing signal and a light reception signal serving as an electric signal obtained by receiving the backlight by the light reception unit. The light power detection unit detects power of the signal light by multiplying an integrated value of a multiplication signal obtained by multiplying the synchronizing signal and the light reception signal by the multiplication unit and a power ratio of the signal light to the backlight stored in a predetermined storage unit.

BROADBAND ARBITRARY WAVELENGTH MULTICHANNEL LASER SOURCE

A multi-channel laser source, including: a bus waveguide coupled, at an output end of the bus waveguide, to an output of the multi-channel laser source; a first semiconductor optical amplifier; a first back mirror; a first wavelength-dependent coupler, having a first resonant wavelength, on the bus waveguide; a second semiconductor optical amplifier; a second back mirror; and a second wavelength-dependent coupler, on the bus waveguide, having a second resonant wavelength, different from the first resonant wavelength. In some embodiments the first semiconductor optical amplifier is coupled to the bus waveguide by the first wavelength-dependent coupler, which is nearer to the output end of the bus waveguide than the second wavelength-dependent coupler, the second semiconductor optical amplifier is coupled to the bus waveguide by the second wavelength-dependent coupler, and the first wavelength-dependent coupler is configured to transmit light, at the second resonant wavelength, along the bus waveguide. 1. A multi-channel laser source , comprising:a bus waveguide coupled, at an output end of the bus waveguide, to an output of the multi-channel laser source;a first semiconductor optical amplifier;a first back mirror;a first wavelength-dependent coupler having a first resonant wavelength;a second semiconductor optical amplifier;a second back mirror; anda second wavelength-dependent coupler having a second resonant wavelength, different from the first resonant wavelength; a first end coupled to the first back mirror, and', 'a second end,, 'the first semiconductor optical amplifier comprising a channel port connected to the second end of the first semiconductor optical amplifier;', 'a bus output connected to a first portion of the bus waveguide; and', 'a bus input, connected to a second portion of the bus waveguide more distant from the output end of the bus waveguide than the first portion of the bus waveguide;, 'the first wavelength-dependent coupler comprisingthe second ...

Independent control of emission wavelength and output power of a semiconductor laser

Methods for driving a tunable laser with integrated tuning elements are disclosed. The methods can include modulating the tuning current and laser injection current such that the laser emission wavelength and output power are independently controllable. In some examples, the tuning current and laser injection current are modulated simultaneously and a wider tuning range can result. In some examples, one or both of these currents is sinusoidally modulated. In some examples, a constant output power can be achieved while tuning the emission wavelength. In some examples, the output power and tuning can follow a linear relationship. In some examples, injection current and tuning element drive waveforms necessary to achieve targeted output power and tuning waveforms can be achieved through optimization based on goodness of fit values between the targeted and actual output power and tuning waveforms.

Packaging Assembly for High-Speed Vertical-Cavity Surface-Emitting Laser

A packaging assembly for a high-speed vertical-cavity surface-emitting laser (VCSEL) mainly applies a lens assembly consisted of several prisms to split a laser beam emitted by a VCSEL element so as to guide a small portion of the laser beam back to a monitor photodiode (MPD) and the rest of the laser beam to travel away along an optical axis. Such a spectacular design of the lens assembly can not only relieve the VCSEL element from a position right under the optical axis, but can also reduce signal loss by shorting a length of a bonding wire for a corresponding pin through disposing the VCSEL element further close to the corresponding pin. Thereupon, a defect of lights reflected from a lens or a translucent plate on a cap can be substantially improved. 1. A packaging assembly for a high-speed vertical-cavity surface-emitting laser , comprising:a header, having an upper surface and a lower surface;a cap, covering the header and thus forming an accommodation space between the cap and the header, furnished thereon with an optical window, an optical axis being defined to penetrate the optical window by being perpendicular to the upper surface of the header;a laser element, located on the upper surface of the header, being to emit a laser beam;a monitor photodiode (MPD), located on the upper surface of the header, being to receive a portion of the laser beam emitted by the laser element for monitoring and feedback-controlling a luminous power of the laser element; anda prismatic assembly, located above the upper surface of the header by being positioned between the laser element and the optical window and also between the monitor photodiode and the optical window;wherein both the laser element and the monitor photodiode are not located on the optical axis, the prismatic assembly has thereinside a partially reflecting surface, the laser beam emitted by the laser element is directed into the prismatic assembly so as to split into a first light beam and a second light beam ...

Operating a laser diode in an optical network

A method and a device is provided driving an optical laser diode ( 710, 711 ) during operation in an optical communication network, by determining a laser transfer function ( 741, 742 ) during operation of the laser diode ( 710, 711 ) and providing a control signal ( 750, 749 ) for driving the laser diode ( 710, 711 ) according to the laser transfer function ( 741, 742 ). Further, a method for driving a first and a second optical laser diode during operation in an optical communication network is provided. Furthermore, an optical amplifier and a communication system is suggested.

Proximity sensor

The present disclosure relates to a proximity sensor. The proximity sensor includes: a light emitter (for example, a vertical cavity surface emitting LASER (VCSEL)) configured to irradiate light to a target to be inspected; a first light receiver having a first crosstalk characteristic, configured to detect an external reflected light from a target to be inspected within a first detection region (for example, 0˜5 cm approximately); and a second light receiver having a second crosstalk characteristic different from the first crosstalk characteristic, configured to detect an external reflected light from a target to be inspected within a second detection region (for example, 3˜60 cm approximately) relatively further than the first detection region.

Optical amplification device and optical amplification method

To limit the number of excitation laser diodes (LDs) in an optical amplification device provided with a redundant excitation LD configuration, the optical amplification device is provided with: an excitation unit which outputs a plurality of excitation lights generated by a plurality of excitation light sources; a first distributing unit of which inputs are connected to the plurality of excitation light sources and which branches input lights and then outputs branched lights as a plurality of first distributed lights; a plurality of second distributing units of which inputs are connected to the first distributing unit and which combines and branches input lights and then outputs branched lights as a plurality of second distributed lights; and a plurality of gain mediums which are respectively excited by the plurality of second distributed lights.

Optoelectronic packages having magnetic field cancelation

A stacked optoelectronic packaged device includes a bottom die having a top surface including bottom electrical traces and a light source die coupled to ≧1 bottom electrical traces. A first cavity die is on the bottom die. An optics die is on the first cavity die and a second cavity die on the optics die. A mounting substrate is on the second cavity die including top electrical traces. A photodetector die is optically coupled to receive light from the light source. The bottom and top electrical traces are both positioned substantially symmetrically on sides of a mirror plane so that when conducting equal and opposite currents a first magnetic field emanating from the first side and a second magnetic field emanating from the second side cancel one another to provide a reduction in magnetic flux density by more than 50% at one or more die locations on the optics die.

PHASE RESPONSE MEASUREMENT METHOD AND APPARATUS

An apparatus at least includes a processor to, after a first signal passes through a narrowband photodetector, perform frequency mix of the first signal with a first reference signal and a second reference signal respectively and perform noise reduction, to obtain a first detection signal and a second detection signal. The first signal is obtained after a measurement signal passes through a filtering module of an optical transmitting end, the measurement signal being transmitted in a path of multiple branches, signals not transmitted in other paths of the multiple branches, a frame structure of the measurement signal including at least one two-tone signal, two tones in the two-tone signal having a fixed tone interval. The processor is to calculate group delays at multiple frequency bins according to the first detection signal and the second detection signal; and determine a phase response of the filtering module of the optical transmitting end in the path according to the group delays at multiple frequency bins.

Laser power controller

A system for transmitting a sequence of at least two data bursts in a fibre optical communications system includes: selection circuitry configured to select one of a data input value, a logical high value or a logical low value such that the selection circuitry selects the data input value during a data transmission period during a defined burst period and selects one of the logical high value and the logical low value during an extension time period during the defined burst period and immediately following the data transmission period, such that for the sequence of at least two bursts, at least one burst has a logical low value extension period and at least one burst has a logical high value extension period; drive circuitry configured to apply a current to a laser diode, the current corresponding to the value selected by the selection circuitry during the defined burst period or a zero value otherwise, the current being such that the laser diode is configured to provide an optical output; an optical sensor module configured to provide a sensor module output corresponding to the optical output of the laser diode; wherein the sensor module output is configured to provide an electrical output proportional to the laser diode's optical output corresponding to the logical high value and the logical low value in the sequence of at least two bursts, and further configured to provide an output corresponding to an average value of the sensor module output during only the data transmission period during the sequence of bursts; and a controller configured to receive values regarding desired minimum and maximum optical output power levels of the laser diode and to receive the electrical output from the optical sensor module proportional to the optical output power level corresponding to the logical high and the logical low values, and to receive the output corresponding to the average value of the sensor module output during only the data transmission period during the ...

Optical element module

An optical element module includes a casing having a bottom plate, a temperature-adjusting unit being mounted on the bottom plate in the casing and having at least a lower layer portion and an upper layer portion positioned above the lower layer portion, a support member mounted on the temperature-adjusting unit in the casing, and a semiconductor laser element being mounted on the support member and outputting a laser light to a forward side. The upper layer portion of the temperature-adjusting unit projects at a backward side of the semiconductor laser element relative to the lower layer portion.

System and method for controlling collocated multiple wavelength tuned lasers

Systems and methods are disclosed herein for controlling laser beams for a plurality of collocated laser assemblies. The laser beams are optimized by controlling outputs of a primary power source (current for generating a laser beam) and a secondary power source (heating device) for each of the respective laser assemblies. The states of the power supply may be cycled and modulated to provide optimal performance.

INTEGRATED HIGH-POWER TUNABLE LASER WITH ADJUSTABLE OUTPUTS

A tunable laser that includes an array of parallel optical amplifiers is described. The laser may also include an intracavity N×M coupler that couples power between a cavity mirror and the array of parallel optical amplifiers. Phase adjusters in optical paths between the N×M coupler and the optical amplifiers can be used to adjust an amount of power output from M-1 ports of the N×M coupler. A tunable wavelength filter is incorporated in the laser cavity to select a lasing wavelength. 1. An optical receiving system comprising:a first cavity reflector of a laser formed on a first substrate that is formed of a first semiconductor material;at least one second cavity reflector of the laser formed on a second substrate that is formed of a second semiconductor material that is different from the first semiconductor material;a plurality of optical paths within the laser extending between the first cavity reflector and the at least one second cavity reflector;plural optical amplifiers formed on the second substrate in at least two optical paths of the plurality of optical paths; anda coherent optical receiver formed on the first substrate and having an optical port connected to an output port from the laser.2. The optical receiving system of claim 1 , wherein the laser is configured to provide a local oscillator signal to the coherent optical receiver.3. The optical receiving system of claim 2 , wherein the coherent optical receiver comprises an integrated phase-diverse photonic circuit.4. The optical receiving system of claim 2 , wherein the coherent optical receiver comprises an integrated polarization-diverse photonic circuit.51. The optical receiving system of claim 1 , further comprising an N×M coupler arranged in the laser to receive light from the first cavity reflector at a first port of the N×M coupler and to distribute the light to N output ports of the N×M coupler claim 1 , where N and M are both greater than .6. The optical receiving system of claim 5 , wherein ...

Visible Light Source

A visible light source capable of preventing degradation of a laser diode and accurately monitoring light of a plurality of wavelengths without hermetic sealing is provided. The visible light source includes a laser diode that is configured to output visible light, and a planar lightwave circuit (PLC) including an input waveguide optically coupled to the laser diode. A space is provided between an emission end face of the laser diode and the input waveguide, and is filled with an inorganic material.

SEMICONDUCTOR LASER, LIGHT SOURCE DEVICE, IMAGE FORMING APPARATUS, IMAGE DISPLAY DEVICE, OBJECT DEVICE, AND COLORED-LIGHT GENERATION METHOD

A semiconductor laser is for generating colored light. The semiconductor laser oscillates in a longitudinal multimode. A width of a wavelength band with an intensity equal to or more than −20 dB relative to a peak intensity in a spectrum distribution of output light is equal to or less than 15 nm. A light source device may include The semiconductor laser; a wavelength estimating device configured to estimate a wavelength λ of light from the semiconductor laser; and an emission-light intensity setting unit configured to set an emission light intensity of the semiconductor laser in accordance with an estimation result by the wavelength estimating device. 1. A semiconductor laser for generating colored light , wherein the semiconductor laser oscillates in a longitudinal multimode , and a width of a wavelength band with an intensity equal to or more than −20 dB relative to a peak intensity in a spectrum distribution of output light is equal to or less than 15 nm.2. A light source device comprising:{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'the semiconductor laser according to ;'}a wavelength estimating device configured to estimate a wavelength λ of light from the semiconductor laser; andan emission-light intensity setting unit configured to set an emission light intensity of the semiconductor laser in accordance with an estimation result by the wavelength estimating device.3. The light source device according to claim 2 , wherein if wavelengths included in the wavelength band are λ claim 2 , λ claim 2 , λ claim 2 , . . . claim 2 , λ claim 2 , and intensities corresponding to the wavelengths in a spectrum are I claim 2 , I claim 2 , I claim 2 , . . . claim 2 , I claim 2 , λ=Σ(λ*I)/Σ(I) (where k=1 claim 2 , 2 claim 2 , 3 claim 2 , . . . claim 2 , n) is satisfied.4. The light source device according to claim 2 , wherein the wavelength estimating device includes:a light receiving element configured to receive light from the semiconductor laser;a temperature sensor ...

CORE-SHELL QUANTUM DOTS AND METHOD OF SYNTHESIZING THEREOF

There is provided a quantum dot comprising a core comprising a semiconductor and a shell substantially covering the core. The core has a first side and a second side opposite the first side. The core is disposed eccentrically inside the shell such that the shell is thinnest at the first side and thickest at the second side. Moreover, the shell has a thickness of greater than or equal to zero at the first side. The core and the shell have different respective lattice constants such that the shell exerts a straining force on the core. The straining force is configured to modify an excitonic fine structure of the core. 1. A quantum dot comprising:a core comprising a semiconductor;a shell substantially covering the core;the core having a first side and a second side opposite the first side, the core disposed eccentrically inside the shell such that the shell is thinnest at the first side and thickest at the second side, the shell having a thickness of greater than or equal to zero at the first side; andthe core and the shell having different respective lattice constants such that the shell exerts a straining force on the core, the straining force configured to modify an excitonic fine structure of the core.2. The quantum dot of claim 1 , wherein the core comprises CdSe and the shell comprises CdS.3. The quantum dot of claim 1 , wherein the core comprises a wurtzite crystal structure and the first side comprises a (0001) facet of the wurtzite crystal structure.4. The quantum dot of claim 1 , wherein a thickness of the shell is less than about 1 nm at the first side.5. The quantum dot of claim 1 , wherein the straining force comprises a biaxial force compressing the core in directions perpendicular to an axis running through the first side and the second side.6. The quantum dot of claim 1 , wherein the shell is substantially six-fold symmetrical about an axis running through the first side and the second side.7. The quantum dot of claim 1 , wherein a thickness of the ...

Operating vertical-cavity surface-emitting lasers

Methods, systems, and computer-readable mediah are provided for operating a vertical-cavity surface-emitting laser. Operating a vertical-cavity surface-emitting laser can include sending a signal to a driver to decrease an optical power of a vertical cavity surface emitting laser transmitter, and sending a signal to the driver associated with increasing the optical power by a particular amount in response to determining that the optical power is insufficient for reception by a receiver.

Closed Loop Optical Modulation Amplitude Control

Systems and methods are provided for a low frequency AC comparison circuit. The low frequency AC comparison circuit includes circuitry configured to receive a monitoring signal generated by an optical detector, the monitoring signal being proportional to an amount of light generated by an optical transmission device that transmits based on a data signal that is received by an optical driver. The comparison circuit is further configured to generate a modulation current control signal that is transmitted to the optical driver based on a comparison of a low frequency AC component of the monitoring signal and a correlated low frequency AC component of the data signal.

Pulsed laser device

A pulsed laser device includes: a semiconductor laser device that outputs laser light having a single wavelength; a semiconductor optical amplifier that receives the laser light output from the semiconductor laser device and amplifies the laser light to output; and a semiconductor-optical-amplifier driver that supplies a pulse-modulated semiconductor-optical-amplifier driving current to the semiconductor optical amplifier.

METHOD FOR SCANNING WAVELENGTH OF EXTERNAL CAVITY LASER

A system and method for scanning the wavelength of an external cavity laser uses synchronized angular motions of two mirrors. By adjusting the angular motions in a selected ratio, it is possible to change the lasing wavelength of the cavity without mode-hops. The mode-hop free ratio of angular motions is determined by simultaneously satisfying the conditions of wavelength selected by diffraction angle from a diffraction grating, and the length of the external cavity. 1. An apparatus , comprising:a first reflector rotatable about a first axis and situated to receive an intracavity laser beam of an external cavity laser from a diffraction grating and to direct the intracavity laser beam along a first direction; anda second reflector rotatable about a second axis and situated to retro-reflect the intracavity laser beam received from the first reflector back to the first reflector and to the diffraction grating.2. The apparatus of claim 1 , wherein the first reflector and second reflector are situated to rotate separately so as to vary an angle of the intracavity laser beam received from the diffraction grating that corresponds to a variation of a lasing wavelength of the external cavity laser over a predetermined range and so as to vary a cavity length of the external cavity laser.3. The apparatus of claim 2 , wherein a variation of the angle and a variation of the cavity length based on rotations of the first reflector and the second reflector correspond to the variation in the lasing wavelength of the external cavity laser without mode hopping over the predetermined range.4. The apparatus of claim 2 , wherein the predetermined range is larger than a longitudinal mode spacing of the external cavity laser.5. The apparatus of claim 3 , wherein the predetermined range corresponds to at least 0.04% of a center wavenumber of the intracavity laser beam.6. The apparatus of claim 2 , wherein a variation of the cavity length and a variation of the lasing wavelength based on ...

LIGHT-EMITTING DEVICE AND DISTANCE MEASUREMENT DEVICE

Provided is a technology for suppressing variations in the waveform of a light emission pulse caused by various factors in a light-emitting device. A light-emitting device is provided with: a light source in which relaxation oscillation occurs immediately after energization; a light source drive circuit which includes a differentiation circuit having a resistor and a capacitor connected in parallel, and in which a switching element for voltage application is connected in series with the differentiation circuit; a power supply circuit ; a light-reception element which detects pulsed light emitted from the light source ; and a voltage control unit which controls an output voltage from the power supply circuit in correspondence with the waveform of the detected pulsed light. 1. A light emitting device comprising:a light source that emits pulsed light having relaxation oscillation immediately after being supplied with electric current;a light source driving circuit that includes a differentiation circuit having a resistor and a capacitor in parallel connection and that includes a switching element for applying voltage in serial connection to the differentiation circuit, and the light source driving circuit being serially connected to the light source;a power supply that applies voltage to the serial circuit of the light source and the light source driving circuit;a pulsed light measuring part that measures the pulsed light emitted from the light source; anda voltage controlling part that controls the voltage to be applied to the light source in response to the waveform of the pulsed light measured by the pulsed light measuring part.2. The light emitting device according to claim 1 , further comprising:a temperature measuring part,wherein the voltage controlling part controls the voltage to be applied to the light source on the basis of the temperature measured by the temperature measuring part.3. The light emitting device according to claim 1 , wherein the voltage ...

METHOD FOR CONTROLLING WAVELENGTH TUNABLE LASER

A method for controlling a wavelength tunable laser is disclosed. The method comprises the steps of: calculating a lasing wavelength from two or more kinds of parameters, the parameters designating the target lasing wavelength; acquiring a driving condition from a memory, the wavelength tunable laser being operable to generate a laser beam of a first wavelength in the driving condition; and calculating another driving condition from the driving condition thus acquired and a wavelength difference between the first wavelength and a second wavelength, the second wavelength corresponding to the lasing wavelength, the wavelength tunable laser being operable to generate a laser beam of the second wavelength in the another driving condition, the wavelength tunable laser being driven in the another driving condition. 1. A method for controlling a wavelength tunable laser , comprising the steps of:receiving two or more parameters to designate a target wavelength of the laser;calculating the target wavelength from the parameters;acquiring a driving condition of a first wavelength from a memory, the first wavelength being different from the target wavelength;calculating an another driving condition from the driving condition acquired from the memory and a wavelength difference between the first wavelength and a second wavelength, the second wavelength being denoted by the target wavelength; anddriving the laser under the another driving condition.2. The method according to claim 1 , wherein the two or more types of parameters include at least two of a parameter indicating a reference frequency claim 1 , a parameter indicating a grid interval claim 1 , and a parameter indicating a channel number.3. The method according to claim 1 , wherein the first wavelength is any of ITU-T grid wavelengths claim 1 , and the second wavelength is different from any of the ITU-T grid wavelengths.4. A method for controlling a wavelength tunable laser claim 1 , comprising the steps of:determining ...

METHOD AND DEVICE FOR CONTROLLING A CARRIER-ENVELOPE PHASE AND/OR AN INTENSITY OF OUTPUT PULSES OF A PULSE LASER DEVICE

A method of controlling output pulses of a pulse laser device () including thin-disk laser medium (), in particular controlling a carrier-envelope phase and/or an intensity noise of the output pulses, includes pumping thin-disk laser medium () of pulse laser device () with multiple pump laser diodes (), having at least one modulated laser diode () powered by current source () with modulation capability, and controlling the output pulses by modulating the output power of the at least one modulated laser diode (), which is modulated by controlling a drive current thereof, wherein the pump laser diodes further include at least one stable laser diode (), having constant output power, and the output power of the at least one modulated laser diode () is smaller than the whole output power of the stable laser diode(s) (). A pulse laser device () is also described. 1. A method of controlling output pulses of a pulse laser device including a thin-disk laser medium , in particular controlling a carrier-envelope phase and/or an intensity of the output pulses , said method comprising the steps ofpumping the thin-disk laser medium of the pulse laser device with multiple pump laser diodes, which include at least one modulated laser diode which is powered by a current source with modulation capability, andcontrolling the output pulses by modulating an output power of the at least one modulated laser diode, which is modulated by controlling a drive current thereof, whereinthe pump laser diodes further include at least one stable laser diode, which has a constant output power, andthe output power of the at least one modulated laser diode is smaller than a whole output power of the at least one stable laser diode.2. The method according to claim 1 , wherein the output of the at least one stable laser diode and the output of the at least one modulated laser diode are combined bya beam combiner which is configured for a free space beam combination, ora fiber beam combiner.3. The method ...

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 ...

SEMICONDUCTOR OPTICAL AMPLIFIER WITH ASYMMETRIC MACH-ZEHNDER INTERFEROMETERS

Described herein are photonic integrated circuits (PICs) comprising a semiconductor optical amplifier (SOA) to output a signal comprising a plurality of wavelengths, a sensor to detect data associated with a power value of each wavelength of the output signal of the SOA, a filter to filter power values of one or more of the wavelengths of the output signal of the SOA, and control circuitry to control the filter to reduce a difference between a pre-determined power value of each filtered wavelength of the output signal of the SOA and the detected power value of each filtered wavelength of the output signal of the SOA. 1. A photonic integrated circuit comprising:a semiconductor optical amplifier to amplify a beam that includes a plurality of wavelengths; anda Mach-Zehnder interferometer integrated in the photonic integrated circuit to receive an amplified beam from the semiconductor optical amplifier, the Mach-Zehnder interferometer configured to apply a tuned loss to a range of the plurality of wavelengths of the amplified beam to compensate for excess gain added to the range of the plurality of wavelengths by a temperature change of the photonic integrated circuit.2. The photonic integrated circuit of claim 1 , wherein the Mach-Zehnder interferometer has a free spectral range greater than or equal to a wavelength range subtended by the plurality of wavelengths in the beam.3. The photonic integrated circuit of claim 1 , further comprising a sensor configured to detect an optical power value of the plurality of wavelengths of the beam.4. The photonic integrated circuit of claim 3 , further comprising control circuitry configured to:receive the optical power value from the sensor;determine a difference between the detected optical power value and a reference optical power value; andcontrol operation of the Mach-Zehnder interferometer to reduce the difference between the detected optical power value and the reference optical power value.5. The photonic integrated ...

LIGHT SOURCE DEVICE

A light source device includes a laser diode configured to emit a laser light used as an illumination light, a determination unit configured to determine one of a plurality of modes as an operation mode of the laser diode based on usage state of the light source device; and a driver configured to drive the laser diode in a condition that a bias current to the laser diode is applied depending on the operation mode determined by the determination unit. 1. A light source device comprising:a laser diode configured to emit a laser light used as an illumination light;a determination unit configured to determine one of a plurality of modes as an operation mode of the laser diode based on a usage state of the light source device; anda driver configured to drive the laser diode in a condition that a bias current to the laser diode is applied depending on the operation mode determined by the determination unit.2. The light source device according to claim 1 , whereinstability of the laser diode varies depending on the mode selected from the plurality of modes, andthe determination unit is configured to select one of the plurality of modes based on the usage state, and is configured to determine the selected mode as the operation mode.3. The light source device according to claim 1 , whereinthe determination unit is configured to select a first mode or a second mode as the operation mode,reliability of an operation of the laser diode in the second mode is lower than that in the first mode, andpower consumption of the laser diode in the second mode is smaller than that in the first mode.4. The light source device according to claim 3 , wherein the driver is configured to apply no bias current to the laser diode if the operation mode is the second mode.5. The light source device according to claim 3 , wherein the driver is configured to apply a bias current having a predetermined magnitude to the laser diode if the operation mode is the first mode.6. The light source device ...

SETTING LASER CURRENT BASED ON MODULATION LEVEL OF AN OPTICAL POWER SENSOR MEASUREMENT

Before writing to a heat-assisted magnetic recording medium, a DC signal modulated with an AC signal is applied to a laser of a read/write head. A modulation level of an optical power sensor is measured, the optical power sensor being coupled to detect optical output of the laser in response to the modulated current. A target value of the DC signal that causes the modulation levels to reach a predetermined value between zero and a maximum value is determined and used to set a bias current for subsequent activation of the laser based. 1. A method , comprising:before writing to a heat-assisted magnetic recording medium via a laser of a read/write head, applying a laser signal to the laser, the laser signal comprising a DC signal modulated with an AC signal;measuring, in response to different values of the DC signal; modulation levels of an optical power sensor that is coupled to detect optical output of the laser in response to the laser signal;determining a target value of the DC signal that causes the modulation levels to reach a predetermined value between zero and a maximum value, the target value defining a threshold current above which the laser begins to emit light; andsetting a bias current for subsequent activation of the laser based on the threshold current.2. The method of claim 1 , wherein the subsequent activation of the laser comprises adding an operational current to the bias current to fully activate the laser for writing to the heat-assisted magnetic recording medium.3. The method of claim 2 , further comprising:determining a slope efficiency based on the modulation level of the optical power sensor; andmodifying the operational current based on the slope efficiency.4. The method of claim 1 , wherein the modulation level of the optical power sensor as a function of the different values of the DC signal comprises an s-shaped curve asymptotically approaching zero as the laser signal becomes small enough not to activate the laser and approaching the ...