Abstract: A closed loop system for controlling laser temperature without the need for additional sensors or other hardware. Embodiments utilize an existing automatic power feedback loop and existing sensors to determine the temperature of a TOSA based on changes in laser bias current, thus avoiding the need for the additional hardware. The automatic power feedback loop will modify the laser bias current as the temperature of the TOSA changes. That is, as the temperature increases, the amount of laser bias current is increased and as the temperature decreases, the amount of laser bias current is decreased. Thus, the laser bias current may be used as feedback for the laser temperature control. Accordingly, when the transceiver module drops below a predetermined temperature, a laser heater current may be controlled to thereby maintain the same laser bias current as at the preset temperature.

Abstract: A laser apparatus in which the elimination of separate optical components to provide intra-cavity polarization and compensation for thermally induced birefringence, and their associated losses, results in an improvement in efficiency and reduction in complexity over prior art designs.

Abstract: The invention is directed to an OSA having a TO-can-type configuration that is relatively low-cost to manufacture and that has functionality for monitoring and controlling the temperature of the laser diode without the need for additional pins or an increase in the size of the OSA. Thus, the OSA typically includes four or five pins at most. These features of the invention are achieved by providing a thermal control circuit, a temperature sensor and a heater that are integrated along with a laser output power monitor photodiode into the submount assembly substrate.

Abstract: In a semiconductor lasers using quantum well gain medium, a quantum well stack is mounted in an epi-down configuration. The epitaxial side of the device may be directly bonded to an efficient heat transport system so that heat may more easily leave the quantum well stack layers and be disposed at a heatsink. Such a device runs cooler and exhibits reduced loss mechanisms as represented by a laser system loss-line. External cavity systems using this configuration may permit a high degree of tunability, and these systems are particularly improved as the tuning range is extended by lowered cavity losses.

Abstract: Provided is a multiple distributed feedback laser device. The laser device includes an active layer, a first diffraction grating, and a second diffraction grating. The substrate includes a first distributed feedback region, a modulation region, and a second distributed feedback region. The first diffraction grating is coupled to the active layer in the first distributed feedback region. The second diffraction grating is coupled to the active layer in the second distributed feedback region. In addition, the laser device includes a first micro heater and a second micro heater. The first micro heater supplies heat to the first diffraction grating. The second micro heater supplies heat to the second diffraction grating. The first micro heater and the second micro heater are controlled independently from each other.

Abstract: A method for controlling wavelengths of a multi-path laser is provided. The method includes: obtaining a difference between an actual output wavelength and a target output wavelength of each laser (S601); obtaining a corrected control amount of a temperature controller of each laser by decoupling calculation according to the difference (S602); and determining a die temperature of each laser according to the corrected control amount of the temperature controller (S603). A system for controlling wavelengths of a multi-path laser includes a multi-path laser (10), a difference module (12), a decoupling module (14), and a temperature control module (16).

Abstract: The controller 170 controls the output power of the semiconductor laser device 100a depending on the temperature of the semiconductor laser device 100a acquired by the temperature sensor 130. The controller 170 references the correspondence table 510 when the sensor temperature Ts is obtained, obtains the output power PWs corresponding to the sensor temperature Ts, and controls the power supply driving circuit 150a so that the output power per unit time of the semiconductor laser device 100a will be the output power PWs. Thus increase in temperature of the semiconductor laser device is able to be prevented through reducing the output power by controlling the amount of power supplied to the semiconductor laser device.

Abstract: A wavelength tunable laser module for DWDM is used, in which a single electroabsorption modulator integrated laser is mounted and an oscillation wavelength is made tunable by temperature control. Driving conditions of a laser and a modulator are determined such that they have approximately the same modulation and transmission characteristics in a temperature control range. Such an electroabsorption modulator integrated laser is used and the driving conditions are incorporated, thereby a small, inexpensive wavelength tunable optical transmitter can be provided.

Abstract: A compact mid-IR laser device utilizes a quantum cascade laser to provide mid-IR frequencies suitable for use in molecular detection by signature absorption spectra. The compact nature of the device is obtained owing to an efficient heat transfer structure, the use of a small diameter aspheric lens and a monolithic assembly structure to hold the optical elements in a fixed position relative to one another. The compact housing size may be approximately 20 cm×20 cm×20 cm or less. Efficient heat transfer is achieved using a thermoelectric cooler TEC combined with a high thermal conductivity heat spreader onto which the quantum cascade laser is thermally coupled. The heat spreader not only serves to dissipate heat and conduct same to the TEC, but also serves as an optical platform to secure the optical elements within the housing in a fixed relationship relative on one another.

Abstract: According to one embodiment of the present invention, an optical package comprises one or more semiconductor lasers coupled to a wavelength conversion device with adaptive optics. The optical package also comprises a package controller programmed to operate the semiconductor laser and the adaptive optics based on modulated feedback control signals supplied to the wavelength selective section of the semiconductor laser and the adaptive optics. The wavelength control signal supplied to the wavelength selective section of the semiconductor laser may be adjusted based on the modulated wavelength feedback control signal such that the response parameter of the wavelength conversion device is optimized. Similarly, the position control signals supplied to the adaptive optics may be adjusted based on the modulated feedback position control signals such that the response parameter of the wavelength conversion device is optimized.

Abstract: A two-beam semiconductor laser device 10 includes: a two-beam semiconductor element LDC having a first and a second semiconductor laser elements LD1 and LD2 that can be driven independently and that are formed integrally on a substrate; and a submount 63 having, mounted on a front part thereof, the two-beam semiconductor laser element LDC with the light-emitting face thereof directed forward and having a first and a second electrode pads 64 and 65 connected to electrodes 61 and 62 of the first and second semiconductor laser element LD1 and LD2 by being kept in contact therewith. The first and second electrode pads 64 and 65 are formed to extend farther behind the two-beam semiconductor laser element LDC, and wires 14 and 16 are wire-bonded behind the two-beam semiconductor laser element LDC.

Abstract: A laser includes a laser source and an power source arranged such that both components have substantially the same cross-section, with cooling fins arranged axially along the length of each element. The components are arranged end-to-end in a series to form an assembly with substantially the same cross-section along the entire length of the assembly. A shroud mounted along the assembly forms a single air channel directing air from a fan along the entire length of the assembly, for cooling both the power source and the laser source with the total air flow from the at least one fan. The laser source and the power source are arranged in series such that the laser source is cooled first, and the subsequent air flow, although slightly warmer from cooling the laser source, is sufficient to cool the power source.

Abstract: A semiconductor laser device has at least one semiconductor laser element, a heat sink having a first bearing area, on which the at least one semiconductor laser element bears, a housing upper part and a housing lower part, which, in the interconnected state, can at least partly surround the semiconductor laser element, and also a sealing for the tight connection of housing upper part and housing lower part. The heat sink services as housing lower part.

Abstract: An optical transmitter includes a light-emitting element, a driving circuit, a temperature detection unit, a storage device and a control circuit. The driving circuit causes, based on an input signal, the light-emitting element to emit an optical signal having a pulse shape. The temperature detection unit detects an ambient temperature of the light-emitting element. The storage device stores temperature characteristics information of the light-emitting element. The control circuit controls the driving circuit based on the ambient temperature detected by the temperature detection unit and the temperature characteristic information stored in the storage device, so that an extinction ratio of the optical signal having the pulse shape becomes substantially constant.

Abstract: An exemplary optical pick-up apparatus of the invention comprises: an optical base; a collimator lens provided on the optical base; a laser source disposed adjacent the collimator lens on the optical base and emitting light that produces heat; and temperature gradient control means, provided between the collimator lens and the laser source on the optical base, for flattening temperature gradient between the collimator lens and its surroundings.

Abstract: The present invention provides a laser diode driving circuit able to reduce the degradation of the optical output from the laser diode even when the characteristic of the laser diode widely scatters. The circuit provides a filter circuit connected in parallel to the laser diode that compensates the frequency dependence of the laser diode. In the invention, the frequency characteristic of this filter circuit may be varied depending on the scattering in the frequency response of the laser diode, or on the temperature characteristic of the diode.

Abstract: An object is to provide a wavelength tunable semiconductor laser device, a controller for the same and a control method for the same, which prevent wavelength drifts. The wavelength tunable semiconductor laser device includes an active region for oscillating a laser beam, and a wavelength tuning region for shifting a wavelength of the laser beam. In this device, a thermal compensation region for converting most of the inputted electric power to heat is provided adjacent to the wavelength tuning region, and the sum of an electric power inputted into the wavelength tuning region and an electric power inputted into the thermal compensation region is always kept constant.

Abstract: An optical transmit assembly having a temperature sensor patterned on an electro-optic transducer die. Due to the close proximity of the electro-optic transducer junction and the temperature sensor, the temperature sensor more accurately measures the temperature of the electro-optic transducer junction. This permits for more refined control of the frequency characteristics of optical light emitted by the electro-optic transducer junction since the emitted optical frequencies of most electro-optic transducers are heavily temperature dependent.

Abstract: A condition or detecting a change in the condition of an optical element of a laser arrangement is detected. An ultrasonic signal is coupled into an optical element such that the ultrasonic signal travels along a path within the optical element, and a transit time or a change in transit time for the ultrasonic signal to travel along the path within the optical element is detected.

Abstract: The present disclosure relates generally to semiconductor lasers and laser projection systems. According to one embodiment of the present disclosure, a method of operating a laser projection system is provided. According to the method, the laser projection system is utilized to display a sequence of pixelized image frames comprising an alternating sequence of relatively high intensity active projection periods ModON and relatively low intensity inactive projection periods ModOFF. A complementary control signal transitions between an active state QON during the relatively high intensity active projection periods ModON and an inactive state QOFF during the relatively low intensity inactive projection periods ModOFF.

Abstract: A semiconductor laser diode using the aluminum gallium, arsenide, gallium indium arsenide phosphide, indium phosphide, (AlGaInAs/GaInAsP/InP) material system and related combinations is disclosed. Both the design of the active layer and the design of the optical cavity are optimized to minimize the temperature rise of the active region and to minimize the effects of elevated active layer temperature on the laser efficiency. The result is a high output power semiconductor laser for the wavelengths between 1.30 and 1.61 micrometers for the pumping of erbium doped waveguide devices or for direct use in military, medical, or commercial applications.

Abstract: An optical transmit assembly in which a laser and temperature sensor are mounted on a first substrate without other heat generating components. Other heat generating components may be mounted on a second substrate that is separated from the first substrate by a thermally resistance mechanism. Accordingly, heat that is generated by other components is not as easily transferred to the laser and temperature sensor. This allows the temperature of the temperature sensor to more closely track the temperature of the laser, and allows for more efficient cooling of the laser.

Abstract: The present invention relates to a wavelength tuneable external-cavity laser module, the laser being tuneable across a predetermined wavelength range and comprising: a thermally stabilised substrate; a gain medium for emitting an optical beam passing through the external cavity along an optical axis, said gain medium being placed in thermal contact with the thermally stabilised substrate; an end mirror for receiving and reflecting the optical beam within the external cavity, and a phase element for controlling the phase of the optical beam and being positioned within the external cavity between the gain medium and the end mirror, wherein said phase element comprises a material having a refractive index that varies in response to changes in temperature and has a transmissivity substantially independent of wavelength across said predetermined wavelength range.

Abstract: Arrangements for combination and fast-axis alignment of fast-axes of diode-laser beams are disclosed. Alignment arrangements include providing each diode-laser with a corresponding alignable fast-axis collimating lens, providing individually alignable mirrors for steering an re-orienting beams from each diode-laser, and providing single diode-laser slab-modules in which the diode-laser beams can be pre-aligned to a common propagation-axis direction, and in which edges and surfaces of the slabs can be used to align the fast and slow-axes of the beams. Beam combination methods include combination by dichroic elements, polarization-sensitive elements, and optical fiber bundles.

Abstract: A laser diode device includes a red laser diode element, a green laser diode element and a blue laser diode element. The red, green and blue laser diode elements are arranged in a single package in a state of being connected to wires for supplying power independently. Additionally, the blue laser diode element is arranged between the red laser diode element and the green laser diode element as viewed from a laser beam-emitting direction.

Abstract: Example embodiments may provide an increased efficiency laser chip and/or a vertical external cavity surface emitting laser (VECSEL) using the same. Example embodiment laser chips may include a substrate; a DBR (distributed Bragg reflector) layer on the substrate, an active layer on the DBR layer having multiple quantum wells excited by a pump beam to generate light, and/or an upper coating layer on the active layer by alternately stacking first and second layers each having different refractive indexes. Thicknesses of the first and second layers may be substantially equal to a quarter of a wavelength of light generated by the active layer.

Abstract: A laser diode package includes a laser diode, a cooler, and a metallization layer. The laser diode is used for converting electrical energy to optical energy. The cooler receives and routes a coolant from a cooling source via internal channels. The cooler includes a plurality of ceramic sheets and a highly thermally-conductive sheet. The ceramic sheets are fused together and the thermally-conductive sheet is attached to a top ceramic sheet of the plurality of ceramic sheets. The metallization layer has at least a portion on the thermally-conductive sheet. The portion is electrically coupled to the laser diode for conducting the electrical energy to the laser diode.

Abstract: A microprocessor is used to control the temperature of a laser emitter and thereby regulate the wavelength of optical signals from the laser. A serial interface in the microprocessor provides input and output lines to a host device, and temperature lookup tables are stored in nonvolatile memory. Control logic processes information stored in the memory as well as information on operating conditions of the laser emitter to precisely control the temperature of the laser emitter. A thermo-electric cooler adjusts the temperature of the laser emitter.

Abstract: A laser source assembly comprises a laser diode for generating a laser beam and a focusing lens for focusing the light beam. A spacer is provided for keeping the diode and the lens at a predetermined distance, and is made of a material of low expansion coefficient. Preferably, the subassembly constituted of the diode, the spacer and the lens is housed in a case made of another material that may have a higher expansion coefficient. A resilient element is provided to continuously keep the diode and the lens abutting on the opposite ends of the spacer.

Abstract: Provided is a vertical cavity surface emitting device. The surface emitting device includes a lower mirror layer emitting light having a long wavelength, an active layer providing an optical gain, a tunnel junction layer for confining a current, and an upper mirror layer, which are sequentially stacked on a compound semiconductor substrate, wherein a heat release layer is formed on side surfaces of at least one of the active layer, the tunnel junction layer and the upper mirror layer by using etching process, and the heat release layer has greater thermal conductivity than at least one of the active layer, the tunnel junction layer and the upper mirror layer.

Abstract: A first mirror (5) that can be located at a reflection position (I) at which an optical path is blocked and a laser beam (a) is reflected, and a second mirror (6) that reflects the laser beam (a) which is reflected by the first mirror (5) are disposed between the condenser lens (2) and the object to be irradiated (4). The first mirror (5) is located at the reflection position (I) so that the laser beam (a) that is transmitted through the condenser lens (2) is sequentially reflected by the first and second mirrors (5 and 6), and an intensity of the laser beam (a) that is again reflected by the first mirror (5) is made to coincide with an intensity of the laser beam (a) that is reflected from the object to be irradiated (4), and the condenser lens (2) is heated in the same manner that the processing laser beam (a) is transmitted through the condenser lens (2) and irradiated on the object to be irradiated (4).

Abstract: A method for assembling an optically pumped solid-state laser having an extended cavity is disclosed. The method comprises the steps of providing a casing, mounting a TEC and a base plate in the casing, and mounting a plurality of laser components on the base plate using a UV and heat curing adhesive. Once the laser components are correctly positioned and aligned on the base plate, the adhesive is pre-cured using UV radiation. Final curing of the adhesive is obtained by subjecting the entire laser package to an ambient temperature of at least 100° C. The base plate is preferably selected to have a CTE similar to that of the laser components in order to facilitate the high temperature curing. A preferred material for the base plate is AlSiC.

Abstract: Apparatus, methods, systems and devices for temperature independent or minimally temperature dependent narrow spectrum laser having an optimized output. The resonator includes at least one volume Bragg grating mirror that changes reflectance with temperature. The volume Bragg grating mirror in combination with a narrow spectrum laser optimizes the laser performance by being temperature tuned to the optimum reflectance. In an embodiment, the volume Bragg grating mirror has a temperature dependent reflectance that compensates for changes in the stimulated emission cross section of the gain medium and leads to a laser with output energy that is independent of temperature.

Abstract: A laser mounted in a casing is driven by and mounted close to its driving circuit. To reduce the effect on the laser of heat generated by the driver circuit, the casing includes a passive heat sink element on which the driver circuit is mounted whereby heat generated by the driver is dissipated by the passive heat sink element.

Abstract: There is provided a mode-locked laser including: a resonator having a pair of resonance mirrors; a solid-state laser medium, disposed in the resonator and outputting oscillating light due to excitation light being incident thereon; an excitation unit that causes the excitation light to be incident on the solid-state laser medium; a mode-locked element, disposed in the resonator for inducing mode locking; and a temperature adjusting unit that adjusts the temperature of the pair of resonance mirrors such that oscillating light of a specific frequency is output from the resonator.

Abstract: A wavelength tunable laser comprises a multiple ring resonator, an input/output side waveguide coupled to a ring resonator, a reflection side waveguide coupled to a ring resonator, a multiple ring resonator, a PLC substrate where the input/output side waveguide and the reflection side waveguide are formed, a high reflection film set on the reflection side waveguide, a SOA connected to the input/output side waveguide through a anti-reflection film, a film heater which is placed above a ring waveguide for wavelength tuning in the PLC substrate and provides heat to the ring waveguide for wavelength tuning, and a adiabatic groove, which restrain conducting heat provided by the film heater to the PLC substrate except the ring waveguide for wavelength tuning.

Abstract: According to an aspect of the present invention, there is provided a laser diode array including: a laser array chip including: a substrate; and at least three of laser diodes that are formed on the substrate; first electrodes that are formed on each of the laser diodes so as to be isolated from one another; a sub-mount; and second electrodes that are formed on the sub-mount so as to correspond to the first electrodes and so as to be isolated from one another, wherein the laser array chip is mounted on the sub-mount through the first electrodes and the second electrodes, and wherein, among contacting surfaces between each of the first electrodes and a corresponding one of the second electrodes, a contacting area of a central one of the contacting surfaces is larger than that of an end one of the contacting surfaces.

Abstract: In a projection display apparatus in which a laser beam source and an optical engine are connected together through an optical fiber, safety is improved against temperature rise in the optical fiber and its periphery. A projection display apparatus includes a temperature sensor 4 provided on the end portion, of the side of an optical engine 6, of an optical fiber group 1 for connecting a laser beam source 5 and the optical engine 6 to each other, in which, by detecting temperature and informing to a controlling unit 71 for controlling the laser beam source 5, when temperature rise exceeding a set value having been set previously is detected, the controlling unit 71 is made to control so as to decrease or stop output from the laser beam source 5.

Abstract: A laser diode array having a plurality of diode bars bonded by a hard solder to expansion matched spacers and mounted on a gas or liquid cooled heatsink. The spacers are formed of a material such as copper/diamond composite material having a thermal expansion that closely matches that of the laser bars.

Abstract: A nitride semiconductor device includes a stem. A heat sink is provided on the stem. At least one nitride semiconductor light-emitting element is connected to the heat sink. A light-detecting element for detecting light from the semiconductor light-emitting element is provided on the stem. A cap for encapsulating therein the heat sink, the semiconductor light-emitting element, and the light-detecting element in a sealed manner is connected to the stem. The space in the cap has an encapsulated atmosphere. The encapsulated atmosphere contains a component for inhibiting diffusion of hydrogen atoms contained in the semiconductor light-emitting element. The present invention suppresses defect due to an increase in operation voltage to increase a ratio of good goods thereby improving the fabrication yield of the semiconductor light-emitting device.

Abstract: An optical semiconductor device includes an optical semiconductor element, a metal pattern and at least one thermal conductive material. The optical semiconductor element has a first optical waveguide region and a second optical waveguide region. The second optical waveguide region is optically coupled to the first optical waveguide region and has a heater for changing a refractive index of the second optical waveguide region. The metal pattern is provided on an area to be thermally coupled to a temperature control device. The thermal conductive material couples the metal pattern with an upper face of the first optical waveguide region of the optical semiconductor element. The thermal conductive material is electrically separated from the first optical waveguide region.

Abstract: A laser diode package includes a laser diode, a cooler, and a metallization layer. The laser diode is used for converting electrical energy to optical energy. The cooler receives and routes a coolant from a cooling source via internal channels. The cooler includes a plurality of ceramic sheets and a highly thermally-conductive sheet. The ceramic sheets are fused together and the thermally-conductive sheet is attached to a top ceramic sheet of the plurality of ceramic sheets. The metallization layer has at least a portion on the thermally-conductive sheet. The portion is electrically coupled to the laser diode for conducting the electrical energy to the laser diode.

Abstract: The present invention relates to a solid-state laser module, and so on, having a structure for enabling optical output of high quality to be obtained. The solid-state laser module includes a vacuum container with windows, and a heat sink, a solid-state laser medium, and a pair of transparent members are housed in the vacuum container in an integrally assembled state. The solid-state laser medium and the pair of transparent members respectively have disk shapes, and the pair of transparent members sandwich the solid-state laser medium. The thermal conductivity of each of the pair of transparent members is higher than the thermal conductivity of the solid-state laser medium.

Abstract: A semiconductor laser device according to the present invention includes: a semiconductor laser chip 1 for emitting laser light; a stem 3, 4 for supporting the semiconductor laser chip; a plurality of terminal electrodes, inserted in throughholes provided in the stem 3, 4, for supplying power to the semiconductor laser chip; and a cap 5 having an optical window 6 which transmits laser light and being affixed to the stem 3, 4 so as to cover the semiconductor laser chip 1. Between the stem 3, 4 and the terminal electrodes 7, this device includes insulation glass 8, which does not release silicon fluoride gas when heated to a temperature of no less than 700° C. and no more than 850° C.

Abstract: The invention concerns a device for longitudinal pumping of an amplifying laser medium comprising at least one laser diode capable of emitting at least one laser beam, means for focusing said laser beam onto said amplifying laser medium and means for collimating said laser beam capable of generating a collimated laser beam. The invention is characterized in that said focusing means comprise at least one mirror, said mirror being arranged such that said collimated beam is reflected towards the amplifying medium.

Abstract: A monolithic passively Q switched microlaser includes an optically transparent heat conductive element bonded to a gain medium, which is in turn bonded to a saturable absorber, which may also be bonded to a second optically transparent heat conductive element. Only the gain medium and saturable absorber are disposed within the laser resonator.

Abstract: The present invention pertains to a composite slab laser gain medium with an undoped core and at least one doped gain medium section disposed on at least one side of that core. The gain medium is constructed so as to mitigate the effects of thermal and mechanical stresses within it and also allow for impingement cooling of the doped gain medium section.

Abstract: A gas detection laser diode device and gas detection unit including the gas detection laser diode device having a hermetically sealed housing with electrical connectors at the bottom and a window, and inside the housing a laser diode and thermistor mounted on one stage of a thermo element. The thermo element is connected with the other stage to the base of the housing. Collimating means are arranged in the laser beam between the laser diode and the window. The window is tilted in respect to the axis of the laser beam such, that the ordinary reflection of the laser beam is steered off the laser beam axis and at least does not impinge on the laser diode. Preferably the collimating means and the laser diode are mounted on a same surface for holding them on the same temperature. The new device allows the detection of toxic gases with reduced detection limits over the prior art. The arrangement further claims a method to achieve reduced detection limits for gases.

Abstract: A gas discharge laser system bandwidth control mechanism and method of operation for controlling bandwidth in a laser output light pulse generated in the gas discharge laser system is disclosed which may comprise a bandwidth controller which may comprise an active bandwidth adjustment mechanism; a controller actively controlling the active bandwidth adjustment mechanism utilizing an algorithm implementing bandwidth thermal transient correction based upon a model of the impact of laser system operation on the wavefront of the laser light pulse being generated and line narrowed in the laser system as it is incident on the bandwidth adjustment mechanism. The controller algorithm may comprises a function of the power deposition history in at least a portion of an optical train of the gas discharge laser system, e.g., a linear function, e.g., a combination of a plurality of decay functions each comprising a respective decay time constant and a respective coefficient.

Abstract: Aspects of the present invention are directed to the use of optical gain structures that include alternating layers of gain medium and transparent heat conductors in which the gain medium itself functions as a correction optic. The gain medium changes to an optimum or desired shape because of the thermal changes occurring as the materials of the optical gain structure(s) reach a desired optical output condition. At the desired optical output conditions, the gain medium conforms to a desired shape. The desired shape may be, for example, that of an optical surface of a transparent heat conductor. By designing the initial shape of the gain medium such that the physical contact with the transparent heat conductor is maximized at the desired optical output conditions, conductive heat transfer between the gain medium and heat conductor(s) is maximized at the desired optical output condition.