Abstract: A semiconductor laser has a first diffractive grating area. The first diffractive grating area has a plurality of segments. Each segment has a first area including a diffractive grating and a second area that is space area combined to the first area. Optical lengths of at least two of the second areas are different from each other. A refractive-index of each of the segments are changeable.

Abstract: The invention refers to a laser device comprising a plurality of linear resonator tubes (12) for a gas to be excited, the resonator tubes being in fluidic communication with each other and forming a common tubular space, connecting elements (20) arranged in corners between adjacent resonator tubes of a common tubular space, excitation means (50) for the resonator tubes for exciting the gas in the resonator tubes for generating a laser light, mirrors (22) arranged in the connecting elements for reflecting laser light between the resonator tubes, and a partially reflecting output coupler (42) for coupling out a laser beam. The resonator tubes are arranged in the shape of a helix, surrounding a free central space. The invention also relates to a method for generating laser light with such a laser device.

Abstract: A temperature controlled multi-channel transmitter optical subassembly (TOSA) may be used in a multi-channel optical transceiver. The temperature controlled multi-channel TOSA generally includes an array of lasers optically coupled to an optical multiplexer, such as an arrayed waveguide grating (AWG), to combine multiple optical signals at different channel wavelengths. The lasers may be thermally tuned to the channel wavelengths by establishing a global temperature for the array of lasers and separately raising local temperatures of individual lasers in response to monitored wavelengths associated with the lasers. A temperature control device, such as a TEC cooler coupled to the laser array, may provide the global temperature and individual heaters, such as resistors adjacent respective lasers, may provide the local temperatures. The optical transceiver may be used in a wavelength division multiplexed (WDM) optical system, for example, in an optical line terminal (OLT) in a WDM passive optical network (PON).

Abstract: A thermoelectric module includes a first insulated substrate having a first opposing surface, a second insulated substrate having a second opposing surface, the second opposing surface faces the first opposing surface, a plurality of electrodes formed on the first and second opposing surfaces, a plurality of thermoelectric transducers provided between the first insulated substrate and the second insulated substrate, the plurality of thermoelectric transducers electrically connected with one another in series and/or in parallel via each electrode, and a conducting circuit electrically connecting the plurality of electrodes with an external power source, wherein the first insulated substrate includes a substrate body having the first opposing surface and a projecting portion being formed continuously from the substrate body and extending in a direction that intersects the substrate body, and the projecting portion includes a fixing surface extending in the direction that intersects the substrate body.

Abstract: A temperature controller for a gas laser which controls temperatures of a plurality of temperature-controlled apparatuses including a first temperature-controlled portion requiring a high-precision temperature-control and a second temperature-controlled portion requiring a low-precision temperature-control as compared with the first temperature-controlled portion and allowing a temperature-control with a low or high temperature as compared with the first temperature-controlled portion, comprises a first temperature control portion generating a cooling agent or a heating agent for adjusting a temperature of each first temperature-controlled portion, a second temperature control portion generating a cooling agent or a heating agent for adjusting a temperature of each second temperature-controlled portion, a first piping system connecting the first temperature control portion and each first temperature-controlled portion in parallel, and a second piping system connecting the second temperature control portion an

Abstract: A system for self-aligning assembly and packaging of semiconductor lasers allows reduction of time, cost and testing expenses for high power density systems. A laser package mounting system, such as a modified TO-can (transistor outline can), has modifications that increase heat transfer from the active laser to a heat exchanger or other heat sink. A prefabricated heat exchanger assembly mounts both a laser package and one or more lenses. Direct mounting of a fan assembly to the package further minimizes assembly steps. Components may be physically and optically aligned during assembly by clocking and other indexing means, so that the entire system is self-aligned and focused by the assembly process without requiring post-assembly adjustment. This system can lower costs and thereby enable the use of high powered semiconductor lasers in low cost, high volume production, such as consumer items.

Abstract: An OPS-chip is soldered mirror-structure-side down on an upper surface of diamond-heat spreader. A metal frame is also soldered to the upper surface of the heat-spreader. The lower surface of the diamond heat-spreader is either soldered to, or clamped against, a surface of a heat-sink. The dimensions of the frame and the heat spreader are selected such that at a solidification temperature of the solder at the center of the upper surface of the heat-spreader has an effective CTE comparable with that of the OPS-chip. The lower surface of the heat-spreader can be soldered to the heat sink surface or clamped against the heat-sink surface by the frame.

Abstract: A water-cooled heat-sink for a diode-laser bar includes a copper-cooling-unit having an integral mount thereon for the diode-laser bar. The copper-cooling-unit is attached to a steel base-unit. The base-unit and the cooling-unit are cooperatively configured such that at least one cooling-channel is formed in the cooling-unit by the attachment of the base-unit to the cooling-unit. The cooling-channel is positioned to cool the mount when cooling-water flows through the cooling-channel.

Abstract: A diode-laser bar is mounted on water-cooled heat-sink between two ceramic sub-mounts for electrically isolating cooling-water in the heat-sink from the diode-laser bar. Mounting between the two ceramic sub-mounts also provides for balancing stresses due to differences in coefficient of thermal expansion (CTE) between the sub-mounts and the diode-laser bar. Both sub-mounts are in thermal communication with the heat-sink for providing two-sided cooling of the diode-laser bar.

Abstract: An optically pumped sulfur monoxide (SO) molecular laser is presented. A near infrared pump light source generates a pump light at wavelengths that match wavelengths of a Q-branch or R-branch absorption transition of a b 1?+ excited electronic state of the SO molecule. The pump light is directed to a vessel containing a laser gain medium including gaseous SO and a buffer gas. The gaseous gain medium may be flowed through the region of output light extraction to remove waste heat deposited in the medium. In some examples output light is generated from any of the R-branch, Q-branch, or P-branch emission transitions between the v=0 vibrationless b 1?+ electronic state and the v=1 vibrational x 3?? ground electronic state. In some other examples, output light is generated from P-branch emission transitions between the v=0 vibrationless b 1?+ electronic state and the v=0 vibrationless x 3?? ground electronic state.

Abstract: A laser cooling system includes a substrate, an REO layer of single crystal rare earth oxide including at least one rare earth element positioned on the surface of the substrate, and an active layer of single crystal semiconductor material positioned on the REO layer to form a semiconductor-on-insulator (SOI) device. Light guiding structure is at least partially formed by the REO layer so as to introduce energy elements into the REO layer and produce cooling by anti-Stokes fluorescence. The active layer of single crystal semiconductor material is positioned on the REO layer in proximity to the light guiding structure so as to receive the cooling.

Abstract: A laser system includes an array of lasers that emit light at a number of different, fixed wavelengths. A group of optical transport systems connect to the laser system. Each of the optical transport systems is configured to modulate data signals onto the light from the laser system to create optical signals and transmit the optical signals on one or more optical fibers.

Abstract: Mount for semiconductor laser devices comprises thermally conductive anode and cathode blocks on either side of semiconductor laser device such as laser diode. Interposed between at least the anode block and the anode of the semiconductor laser device is a sheet of conformable electrically conductive material with high thermal conductivity such as pyrolytic highly-oriented graphite. In some embodiments, a second sheet of such electrically and thermally conductive conformable material is interposed between the cathode of the semiconductor laser device and the cathode block. The semiconductor laser device can be either a single laser diode or a diode bar having a plurality of emitters. A thermally conductive, but electrically insulating, spacer of essentially the same thickness as the laser diode or bar surrounds the diode or bar to prevent mechanical damage while still permitting the conformable material to be maintained in a compressed state and directing current through the laser device.

Abstract: [PROBLEM] Providing an optical source that outputs optical frequency modulated light having a constant output optical intensity. [MEANS FOR SOLVING THE PROBLEM] Provided is a light source apparatus that outputs an optical signal having an optical frequency corresponding to a frequency control signal, the light source apparatus including a laser light source section that outputs laser light having an optical frequency corresponding to the frequency control signal; and an optical intensity adjusting section that compensates for intensity change of the laser light to output laser light in which the intensity change caused by a change in the optical frequency is restricted.

Abstract: A thermal shunt is to transfer heat from a sidewall of a device to a silicon substrate. The device is associated with a Silicon-On-Insulator (SOI) including a buried oxide layer. The thermal shunt extends through the buried oxide layer to the silicon substrate.

Abstract: Systems and methods for providing a low stress electrode connection capable of carrying a high electrical current to an edge-emitting device, such as a laser diode are described. Systems and methods for providing mechanisms to allow precise adjustment of the relative position of one heat-sink for an optical edge emitting device relative to an adjacent heat-sink in a stack of heat-sinks are also provided herein.

Abstract: A temperature controller for a gas laser which controls temperatures of a plurality of temperature-controlled apparatuses including a first temperature-controlled portion requiring a high-precision temperature-control and a second temperature-controlled portion requiring a low-precision temperature-control as compared with the first temperature-controlled portion and allowing a temperature-control with a low or high temperature as compared with the first temperature-controlled portion, comprises a first temperature control portion generating a cooling agent or a heating agent for adjusting a temperature of each first temperature-controlled portion, a second temperature control portion generating a cooling agent or a heating agent for adjusting a temperature of each second temperature-controlled portion, a first piping system connecting the first temperature control portion and each first temperature-controlled portion in parallel, and a second piping system connecting the second temperature control portion an

Abstract: A laser package for use in a dermatological treatment device may include a conductive carrier, an insulation layer arranged over a first region of a first side of the conductive carrier, a semiconductor laser device mounted to a second region of the first side of the conductive carrier, and a conductive film secured to the semiconductor laser device and extending over at least a portion of the insulation layer, such that the conductive film is insulated from the conductive carrier by the insulation layer, and wherein a coefficient of thermal expansion of the semiconductor laser device differs from a coefficient of the conductive carrier to which it is mounted by more than 20%.

Abstract: To constitute an optical module comprising a mount and a board that supports the mount, wherein a solid-state laser device that oscillates fundamental laser light, a pump light source that pumps the solid-state laser device, and a wavelength converting device that converts a wavelength of the fundamental laser light oscillated by the solid-state laser device are mounted on the mount, the mount is divided into three blocks, that is, a first block on which a laser medium is mounted, a second block on which the pump light source is mounted, and a third block on which the wavelength converting device is mounted. A side surface or a bottom surface of only the second block is fixed to the board, the first block is fixed to the other side surface of the second block, and the third block is fixed to a side surface of the first block.

Abstract: Provided is a power saving and highly reliable wavelength tunable laser device. A wavelength tunable laser device 10 of the present invention includes: a wavelength tunable laser 11 including: a laser resonator including a light source 111 and wavelength tunable mechanisms 112 and 113; and light loss control units 114a and 114b; a temperature detecting element 12 detecting a temperature of the wavelength tunable laser 11; and a controller 13, wherein the controller 13 obtains temperature information a of the wavelength tunable laser 11 from the temperature detecting element 12, calculates wavelength tunable control parameters d and e and light loss control parameters b1 and b2 based on the temperature information a, controls the wavelength tunable mechanisms 112 and 113 based on the wavelength tunable control parameters d and e, and controls light loss control units 114a and 114b based on the light loss control parameters b1 and b2.

Abstract: A frequency-doubled OPS-laser having a desired output wavelength of 532 nm is tunable about that wavelength by a temperature tuned birefringent filter (BRF). The temperature of the BRF is varied while measuring transmission of a sample of the output through a Nd:YAG crystal having an absorption peak at a wavelength of about 532.4 nm. The peak is detected as a minimum of transmission and the temperature at which that minimum occurs is recorded. From wavelength-change-versus-temperature data for the BRF a temperature is calculated at which the output wavelength has the desired value and is maintained at that value to stabilize the output wavelength.

Abstract: Embodiments of silicon-based thermal energy transfer apparatus for gain medium crystal of a laser system are provided. For a disk-shaped crystal, the apparatus includes a silicon-based manifold and a silicon-based cover element. For a rectangular cuboid-shaped gain medium crystal, the apparatus includes a first silicon-based manifold, a second silicon-based manifold, and first and second conduit elements coupled between the first and second manifolds. For a right circular cylinder-shaped gain medium crystal, the apparatus includes a first silicon-based manifold, a second silicon-based manifold, and first and second conduit elements coupled between the first and second manifolds.

Abstract: Proposed is a light emitting module (1), comprising a semiconductor light emitting device (10) and a thermal switch (20). The thermal switch (20) is arranged to protect the device (10) from over heating. At elevated temperatures the junction of the device (10) may reach a critical level causing catastrophic breakdown of the device. According to the invention, the thermal switch is arranged to shunt the semiconductor light emitting device. This is especially advantageous as the thermal protection offered by the switch (20) correlates directly to the (junction) temperature of the device (10).

Abstract: Systems and methods to improve the performance of nonlinear crystals in a resonant cavity are presented. A humidified purge gas is supplied to a resonant cavity of a laser based illumination source that includes a nonlinear crystal. A small amount of water vapor is added to a clean, dry purge gas to prevent excessive drying of the nonlinear crystal during storage or operation. In some embodiments, a humidity injection system includes at least two parallel flow paths. One flow path includes a humidity injector and another does not include humidity injection. The amount of water vapor added to the purge gas flow is determined at least in part by the relative flow rate between the parallel flow paths. In some embodiments, the amount of water vapor added to the purge gas flow is regulated based on a measurement of humidity in the resonant cavity.

Abstract: This invention relates to semiconductor lasers, and more particularly, to a cooling module for fabricating a liquid-cooled semiconductor laser, a fabricating method, and a semiconductor laser fabricated from the module, wherein the cooling module for a laser makes use of a liquid cooling plate provided with radiating fins to cool the semiconductor chip. After replacement of the traditional micro-channel structure with the radiating fin structure, the present invention effectively reduces the resistance to flow of the cooling liquid, remarkably lowers the pressure decrease of the cooling liquid, makes it easier to seal the cooling liquid, provides stronger heat dissipating capability, effectively elongates the lifetime of the semiconductor laser, and enhances the output power and reliability of the semiconductor laser, alongside the advantages of simple fabrication and low production cost.

Abstract: Embodiments of the invention include a fiber laser cavity package having improved fiber management and thermal management capability and methods of making such fiber laser cavity package. Each element of the fiber laser cavity is grouped into plurality of sections and each section is placed onto a heat conducting surface within the fiber laser cavity package to dissipate unwanted heat from the elements. When the fiber laser cavity is stored in the package, the fiber laser cavity is arranged such that fiber crossings are substantially reduced or eliminated within the package.

Abstract: The invention relates to an optical assembly (1) comprising a pulsed light source (2) for generating primary light pulses (4), a pulse splitter (5) for splitting said primary light pulses (4) into first and second secondary light pulses (7), and a delay element (8) for delaying said second secondary light pulses (7) relative to said first secondary light pulses (6), where the pulse repetition rate of said pulsed light source (2) is variable in order to change a temporal delay between different secondary light pulses (6,7) The invention is characterized in that said optical assembly (1) comprises a thermal insulation (12), a temperature stabilizer (16) or a temperature compensator (13) for said delay element (8) and/or a control circuit (27) for determining and controlling a drift of said pulse repetition rate.

Abstract: A laser diode assembly includes a housing having a housing part and a mounting part, which is connected to the housing part and which extends away from the housing part along an extension direction. A laser diode chip is disposed on the mounting part. The laser diode chip has, on a substrate, semiconductor layers with an active layer for emitting light. The housing part and the mounting part have a main body composed of copper and at least the housing part is steel-sheathed. A first solder layer having a thickness of greater than or equal to 2 ?m is arranged between the laser diode chip and the mounting part. The laser diode chip has a radiation coupling-out area, on which a crystalline protective layer is applied.

Abstract: An optical assembly (OSA) that installs a semiconductor optical device mounted on a thermo-electric controller (TEC) is disclosed. The TEC in the upper plate thereof is mechanically connected to the housing, or to the block stiffly fixed to the housing by a bridge made of stiff material. The bridge preferably extends along the optical axis to show enhanced durability against the impact caused by an external ferrule abutting against the receptacle of the OSA.

Abstract: A compact CO2 slab-laser is contained in a fluid cooled housing having three compartments. One compartment houses discharge electrodes and a laser resonator. Another compartment houses a radio-frequency power supply (RFPS) assembled on a fluid-cooled chill plate and an impedance-matching network. The remaining compartment houses beam-conditioning optics including a spatial filter. The housing and RFPS chill-plate are on a common coolant-fluid circuit having a single input and a single output. The spatial filter is optionally fluid-coolable on the common coolant fluid circuit.

Abstract: Systems and methods of high efficiency amplification of pulsed laser output for high energy ultra-short pulse laser systems are provided herein. According to some embodiments, methods for amplifying pulsed laser output for high energy ultra-short pulse laser systems include receiving pulsed laser output and amplifying the pulsed laser output by propagating the pulsed laser output through a non-silica based gain medium that has been doped with a concentration of rare earth ions, wherein the concentration of the rare earth ions within the gain medium is approximately greater than one percent by weight.

Abstract: A device and corresponding method for cooling electronics is disclosed. The device is an all-solid-state optical cryocooler and can include an optically pumped semiconductor laser (OPSL); a cavity configured to receive and control absorption of the optically pumped semiconductor laser, the cavity having a high reflection (HR) surface and an anti-reflection (AR) surface; and a doped crystal housed within the cavity, the doped crystal configured to cool in response to input of the optically pumped semiconductor laser. The method can include supplying an intracavity optically pumped semiconductor lasers to a doped crystal within a cavity; and configuring the cavity to include a high reflection (HR) surface and an anti-reflection (AR) surface, the HR surface and AR surface formed on or in connection with the doped crystal to increase pump light absorption at the crystal within the cavity.

Abstract: Included are, a module fixing body having a plurality of mounting holes into which laser modules are fitted and accommodated, respectively; an electricity-supplying member having an end provided with electricity-supplying terminals, which are connected to electricity-receiving terminals of the laser module accommodated in the mounting hole; and a cooling member that cools each of the laser modules. A groove in which the electricity-supplying member is accommodated is formed in a surface of the module fixing body, and the cooling member is closely arranged on the surface of the module fixing body.

Abstract: A laser array light source unit 1 includes: a plurality of semiconductor lasers 2 each including a main body portion 2a and a leg portion 2b with two leading electrodes; a laser holder 3 holding the main body portions 2a, and having through-holes for the leg portions 2b; a pressing member 5 for fixing the semiconductor lasers 2 to the laser holder 3; an insulator 4 including a plurality of electrode insertion portions 4f having through-holes for the leading electrodes; and a wiring base 6 for electrically connecting at least two of the semiconductor lasers 2 in series. The insulator 4 includes a connecting portion 4b for connecting the plurality of electrode insertion portions 4f in the same direction in which the plurality of semiconductor lasers 2 are arranged. The wiring base 6 includes first through-holes into which the leading electrodes of the semiconductor lasers 2 are inserted.

Abstract: To efficiently apply jitter to an optical signal using a simple configuration, provided is an optical signal output apparatus that outputs an optical pulse pattern signal including jitter, the optical signal generating apparatus comprising a light source section that outputs an optical signal having an optical frequency corresponding to a frequency control signal; an optical modulation section that modulates the optical signal output by the light source section, according to a designated pulse pattern; and an optical jitter generating section that delays an optical signal passed by the optical modulation section according to the optical frequency, to apply jitter to the optical signal.

Abstract: Laser-induced damage in an optical material can be mitigated by creating conditions at which light absorption is minimized. Specifically, electrons populating defect energy levels of a band gap in an optical material can be promoted to the conduction band—a process commonly referred to as bleaching. Such bleaching can be accomplished using a predetermined wavelength that ensures minimum energy deposition into the material, ideally promoting electron to just inside the conduction band. In some cases phonon (i.e. thermal) excitation can also be used to achieve higher depopulation rates. In one embodiment, a bleaching light beam having a wavelength longer than that of the laser beam can be combined with the laser beam to depopulate the defect energy levels in the band gap. The bleaching light beam can be propagated in the same direction or intersect the laser beam.

Abstract: An optical wavelength sweeping apparatus having a laser diode with an active region, and a coupled pulse generator is disclosed. The pulse generator is configured and operable to provide current drive pulses of relatively short duration and high amplitude to the laser diode to selectively and rapidly heat the active region and the immediate vicinity and produce a rapid wavelength sweep of emitted optical radiation. Methods of driving a laser diode, and measurement systems are disclosed, as are other aspects.

Abstract: A CO2 gas laser device according to the present invention amplifies CO2 laser light that oscillates repeatedly in short pulses having a pulse width of 100 ns or less, and cools a CO2 laser gas which is excited by continuous discharge by circulating the CO2 laser gas by means of forced convection. Therein, an angle ? defined by the optical axis of the amplified CO2 laser beam and the flow direction of the CO2 laser gas caused by the forced convection is determined by both a discharge cross sectional area and a discharge length of a volume in which the CO2 laser gas is excited by discharge, whereby increasing the gain of pulsed laser to achieve pulsed laser light having an extremely high average output power.

Abstract: Two or more lasers or other temperature sensitive optical devices can be disposed in an operating environment, for example in a common enclosure exposed to the environment. The environment can have a temperature that fluctuates, for example in connection with random events, weather, seasons, etc. Each laser's temperature can track the temperature of the environment in steps, with each laser following a distinct temperature track. The lasers can alternate outputting light into a wavelength division multiplexing channel. For example, during one timeframe, one laser can provide an optical communication signal having a wavelength complying with a wavelength division multiplexing criterion. During another timeframe, the other laser can provide an optical signal having substantially the same wavelength. Operating a laser at an elevated temperature can shorten laser lifetime.

Abstract: A system and method for stabilizing a plurality of output frequencies (wavelengths) of a plurality of lasers (106). The laser beams are combined using optical multiplexer (110) and coupled into length-imbalanced (armlength-mismatched) Mach-Zehnder interferometer (MZI) (114) having an optical modulator (e.g. AOM) (122) in one of its arms. The output of the MZI is divided into corresponding beams via optical demultiplexer (128) and each beam is detected by a respective photo-diode (PD) (134). The individual electric signals, so generated, are demodulated using a corresponding plurality of phase-responsive devices (138) and the resulting phase-signals are directed to a plurality of servo-controllers (148) to control the central frequency of the respective lasers (106) via a corresponding plurality of feedback loop circuits (150). The lasers (106) can have different central frequencies which can also be individually tunned using offset modules (141) in the phase-responsive devices (138).

Abstract: An optical transmitter includes a laser configured to emit light, a power of the light increasing with temperature decreasing, a Faraday rotator configured to rotate a polarization direction of the light in accordance with the temperature, and a first polarizer that has a principal axis inclined at a given angle and inputs the light output from the Faraday rotator.

Abstract: A gas laser includes a fan for producing a flow of a laser gas and a heat exchanger including multiple heat exchanger pipes. The heat exchanger further includes two end plates to which the multiple heat exchanger pipes are secured at the opposing ends thereof. The two end plates include openings for supplying a heat exchanger fluid to the multiple heat exchanger pipes. The multiple heat exchanger pipes extend substantially transversely relative to a flow direction of the flow of laser gas.

Abstract: A main amplifier system includes a first reflector operable to receive input light through a first aperture and direct the input light along an optical path. The input light is characterized by a first polarization. The main amplifier system also includes a first polarizer operable to reflect light characterized by the first polarization state. The main amplifier system further includes a first and second set of amplifier modules. Each of the first and second set of amplifier modules includes an entrance window, a quarter wave plate, a plurality of amplifier slablets arrayed substantially parallel to each other, and an exit window. The main amplifier system additionally includes a set of mirrors operable to reflect light exiting the first set of amplifier modules to enter the second set of amplifier modules and a second polarizer operable to reflect light characterized by a second polarization state.

Abstract: The laser device includes a semiconductor laser element having an emission surface from which laser light is emitted, an optical fiber having an end part facing the emission surface, and an optical fiber supporting member which (i) supports the optical fiber and (ii) has a bonding pad to which the optical fiber is fixed by solder. The optical fiber supporting member includes a beam part having (i) a first main surface on which the bonding pad is provided and (ii) a second main surface opposite to the first main surface, and a pillar part which is fixed to a base and is joined to the beam part on an end portion of the beam part such that the second main surface and the base face each other while being spatially away from each other.

Abstract: A mount for semiconductor laser devices comprises thermally conductive anode and cathode blocks on either side of a semiconductor laser device such as a laser diode. Interposed between at least the anode block and the anode of the semiconductor laser device is a sheet of conformable material with high thermal conductivity such as pyrolytic highly-oriented graphite. In some embodiments, a second sheet of such thermally conductive conformable material is interposed between the cathode of the semiconductor laser device and the cathode block. The semiconductor laser device can be either a single laser diode or a diode bar having a plurality of emitters. A thermally conductive, but electrically insulating, spacer of essentially the same thickness as the laser diode or bar surrounds the diode or bar to prevent mechanical damage while still permitting the conformable material to be maintained in a compressed state.

Abstract: Provided is an optical module in which a temperature of a semiconductor element to be subjected to temperature control is controlled to fall within a desired operating temperature range regardless of whether an environmental temperature is outside or inside the operating temperature range of the semiconductor element, and which is stably operated with low power consumption. A control section 30 determines, based on the environmental temperature having a temperature range of from a first temperature to a second temperature, a target temperature from a predetermined operating temperature range of from a third temperature to a fourth temperature. The control unit 30, an ATC circuit 34, a TEC control IC 12, and a TEC 24 control the temperature of a laser module 20 to become the target temperature. The first temperature is lower than the third temperature, and the second temperature is higher than the fourth temperature.

Abstract: An optical assembly (OSA) that installs a semiconductor optical device mounted on a thermo-electric controller (TEC) is disclosed. The TEC in the upper plate thereof is mechanically connected to the housing, or to the block stiffly fixed to the housing by a bridge made of stiff material. The bridge preferably extends along the optical axis to show enhanced durability against the impact caused by an external ferrule abutting against the receptacle of the OSA.

Abstract: A hybrid external cavity laser (HECL) system comprises a diode laser, collection and collimation optics, and a volume Bragg grating, emits radiation at a single wavelength with a short-term wavelength stability in the order of at least one part in a billion The wavelength stability is achieved by use of a thermal management system, comprising inner and outer housings, each containing a temperature sensor, and electronic circuitry that monitors the temperatures and controls both the laser diode current and a thermoelectric cooler based on temperatures determined from said temperature sensors. The laser system is packaged in a compact enclosure that minimizes waste heat, facilitating use in applications that have heretofore employed stable, single-frequency lasers, including He—Ne lasers.

Abstract: The existing diodes in an LED or laser diode package are used to measure the junction temperature of the LED or laser diode. The light or laser emissions of a diode are switched off by removing the operational drive current applied to the diode package. A reference current, which can be lower the operational drive current, is applied to the diode package. The resulting forward voltage of the diode is measured using a voltage measurement circuit. Using the inherent current-voltage-temperature relationship of the diode, the actual junction temperature of the diode can be determined. The resulting forward voltage can be used in a feedback loop to provide temperature regulation of the diode package, with or without determining the actual junction temperature. The measured forward voltage of a photodiode or the emissions diode in a diode package can be used to determine the junction temperature of the emissions diode.

Abstract: A laser system having a cooling apparatus is disclosed. The laser system includes a resonator, a gain medium and multiple heat-absorbing discs. The resonator is formed by a first mirror and a second mirror. The gain medium, which is contained within the resonator, is collectively formed by a group of gain medium segments. Each of the gain medium segments is preferably in the shape of a cylindrical disc. The heat-absorbing discs are interleavely disposed among the gain medium segments to provide face cooling for the gain medium segments during the operation of the laser system.