Abstract: A wavelength converter is provided with an infrared light source (1) for emitting a fundamental wave having a wavelength of 2000 nm or shorter, a wavelength conversion element (3) composed of a nonlinear optical crystal having a periodical polarization reversal structure and adapted to convert a fundamental wave emitted from the infrared light source (1) into a harmonic wave, and a heater (4) for heating the wavelength conversion element (3). The period of the polarization reversal structure is designed so that a quasi phase matching temperature of the fundamental wave and the harmonic wave is 40° C. or higher. The heater (4) heats the wavelength conversion element (3) to a temperature at which quasi phase matching is established, and the nonlinear optical crystal contains a lithium niobate or lithium tantalate including at least any one of additives Mg, In, Zn and Sc as a main component. Thus, optical damage can be suppressed and visible light absorption attributed to ultraviolet light can be reduced.

Abstract: An EUV light source of the present invention is capable of using a saturable absorber stably and continuously in a high heat load state. A saturable absorber (SA) device is disposed on a laser beam line to absorb feeble light, such as self-excited oscillation light, parasitic oscillation light or return light. SA gas from an SA gas cylinder and buffer gas from a buffer gas cylinder are mixed to be a mixed gas. The mixed gas is supplied to an SA gas cell via a supply pipeline, and absorbs the feeble light included in the laser beam. The mixed gas is exhausted via an exhaust pipeline, and is sent to a heat exchanger. The mixed gas, cooled down by a heat exchanger, is sent back to the SA gas cell by a circulation pump.

Abstract: A photonic system and method are provided. The system includes an optical source configured to generate a carrier signal; and a modulator configured to modulate the carrier signal with a radio frequency, (“RF”) input signal to generate a modulated signal. The system also includes an optical filter configured to filter the modulated signal to generate a vestigial sideband modulated signal; and an optical detector configured to demodulate the vestigial sideband signal to generate an RF output signal. The system further includes a wavelength controller module configured to set an operating parameter of the optical source.

Abstract: A beam alignment chamber extending in a length direction comprising a base having a front edge, and two side edges, first and second opposed side walls connected to the base, and extending along the length of the base, a front wall located at the front edge of the base having an output opening. The beam alignment chamber further comprises a plurality of arrays of light sources disposed to direct light beams through the first or second side walls, and a plurality of reflectors mounted on the base, each having independent yaw and pitch adjustments, each reflector being paired with a corresponding array of light sources, the base-mounted reflectors being disposed to direct the light beams along the length of the beam alignment chamber through the output opening forming an aligned two-dimensional array of parallel light beams.

Abstract: Described is a method for controlling the wavelength of a laser in a wavelength division multiplexed (WDM) system. The method includes generating broadband light having a dithered optical power and a wavelength spectrum that includes a plurality of WDM wavelengths. The broadband light is spectrally filtered to generate a spectrally-sliced optical signal having a wavelength spectrum that includes one of the WDM wavelengths. The spectrally-sliced optical signal is injected into a laser and a dithered optical power of the laser is determined. A parameter of the laser is controlled in response to the determination of the dithered optical power to thereby align a wavelength of the laser to the wavelength spectrum of the spectrally-sliced optical signal.

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 light source apparatus includes a first laser array light source that emits first-wavelength light, and a second laser array light source that emits second-wavelength light, the second wavelength being different from the first wavelength. The first laser array light source includes a first fundamental wave laser array that produces first fundamental wave light having a first original wavelength, and a first wavelength conversion element that wavelength-converts the first fundamental wave light into the first-wavelength light. The second laser array light source includes a second fundamental wave laser array that produces second fundamental wave light having a second original wavelength different from the first original wavelength, and a second wavelength conversion element that wavelength-converts the second fundamental wave light into the second-wavelength light.

Abstract: A light projection optical system is presented. The system comprises a cooling chamber containing: a light source operative at a cool temperature being lower than 240K; a cooler unit capable of cooling said light source to said cool temperature during the light source operation,- an optical window permitting light emergence outside from the cooling chamber; and an optical unit accommodated in the optical path of light emitted by said light source and enabling emergence of this light through said optical window outside from the cooling chamber.

Abstract: A temperature compensation method for laser power in an optical disk drive is provided. A predetermined linear-fitting power curve and a temperature-changing slope curve are previously stored in the optical disk drive. Firstly, an output of laser power is controlled according to the predetermined linear-fitting power curve to read/write data. Next, the temperature of the disk drive is detected. Then, whether the temperature has changed is checked. If the temperature has not changed, the method continues to read/write data. If the temperature has changed, the method obtains a relative slope from the slope curve by use of the temperature of the disk drive, displaces the slope of the predetermined linear-fitting power curve with the obtained relative slope to form a new linear-fitting power curve for replacing the predetermined linear-fitting power curve, and controls the output of laser power.

Abstract: A dual wavelength laser device including a cap, a header, a first laser chip and a second laser chip. The cap includes a cap body and a lens embedded on the cap body. The header forms an accommodating space with the cap. The first laser chip is arranged in the accommodating space and emitting a first laser beam toward the lens. The second laser chip is arranged in the accommodating space and emitting a second laser beam toward the lens.

Abstract: A method is provided for controlling a DBR laser diode wherein front and rear DBR section heating elements are controlled such that the reflectivity of the rear grating portion of the DBR section is lower than the reflectivity of the front grating portion of the DBR section. In this manner, lasing mode selection is dominated by the front grating portion and the front DBR section heating element can be controlled for wavelength tuning. In addition, the rear DBR section heating element can be controlled to narrow the spectral bandwidth of the DBR reflection spectra. Additional embodiments are disclosed and claimed.

Abstract: A diode-laser bar stack includes a plurality of diode-laser bars having different temperature dependent peak-emission wavelengths. The stack is arranged such that the bars can be separately powered. This allows one or more of the bars to be “on” while others are “off”. A switching arrangement is described for selectively turning bars on or off, responsive to a signal representative of the temperature of the diode-laser bar stack, for providing a desired total emission spectrum.

Abstract: Above a Peltier element disposed on a bottom of a case, bases that are platy members of two or more layers and have different expansion coefficients from each other are stacked. At least on a partial region of the base serving as an uppermost layer, a suppression member having an expansion coefficient different from that of the base serving as the uppermost layer is further provided. An optical element is disposed on the base and/or the suppression member. Even when a warp is likely to occur in the Peltier element, a stacked-plate structure of the base, the base, and the suppression member suppresses an occurrence of such a warp, whereby warps hardly occur in the base and the suppression member, and a shift hardly occurs in an optical axis between a beam splitter and an etalon.

Abstract: A semiconductor laser device according to the present invention outputs light while periodically varying the temperature of a semiconductor laser, an optical waveguide, or a diffraction grating, outputs light while causing the optical waveguide or the diffraction grating to mechanically and periodically vary, or causes return light, which varies periodically or non-periodically, to be incident on the semiconductor laser. Since the periodical fluctuation is applied to the temperature of the semiconductor laser, the optical waveguide, or diffraction grating, the periodical mechanical variation is applied to the optical waveguide or the diffraction grating, or the return light is caused to be incident on the semiconductor laser, the semiconductor laser carries out a multimode oscillation from a low output to a high output without shifting between a single mode oscillation and a multimode oscillation.

Abstract: A nonlinear optical device is provided. More specifically, a wavelength conversion device package with less optical loss stabilizes optical alignment under an external environmental change, for example, in a temperature variation by providing a temperature regulating block and a temperature sensor to an optical oscillator and a wavelength modulator and fixing a flexible optical transmitter to the optical oscillator and the wavelength modulator. The wavelength conversion device package includes an optical oscillator comprising a light source for emitting a light; a flexible optical transmitter for transferring the light emitted from the optical oscillator to a wavelength modulator; and the wavelength modulator for receiving the light from the optical transmitter and radiating a wavelength-modulated light.

Abstract: A laser gain medium includes an optical medium configured to transmit a laser beam and having an incident face, a first face, a second face opposing to the first face; and gain media configured to amplify the laser beam while reflecting the laser beam. At least one of the gain media is joined on a first face of the optical medium as a first face gain medium, and at least one of the remaining gain media is joined on a second face of the optical medium as a second face gain medium. The laser beam is incident into the optical medium, and is amplified by the first face gain medium and the second face gain medium while being alternately reflected by the first face gain medium and the second face gain medium.

Abstract: An EUV light source of the present invention is capable of using a saturable absorber stably and continuously in a high heat load state. A saturable absorber (SA) device is disposed on a laser beam line to absorb feeble light, such as self-excited oscillation light, parasitic oscillation light or return light. SA gas from an SA gas cylinder and buffer gas from a buffer gas cylinder are mixed to be a mixed gas. The mixed gas is supplied to an SA gas cell via a supply pipeline, and absorbs the feeble light included in the laser beam. The mixed gas is exhausted via an exhaust pipeline, and is sent to a heat exchanger. The mixed gas, cooled down by a heat exchanger, is sent back to the SA gas cell by a circulation pump.

Abstract: Circuit arrangements for the operation of a pulse laser diode and methods for operating a pulse laser diode include a current source to supply a direct current to the pulse laser diode. The circuit arrangement can provide operation of the pulse laser diode that can be stable and without unintentional shifts in wavelength.

Abstract: Methods and apparatus are disclosed for maximizing performance of an electronic device, such as a display device. Aspects of the exemplary embodiments include operating the electronic device by adjusting power to the device to maintain a predetermined junction temperature of the device independent of the ambient temperature at which the device is operating.

Abstract: One embodiment of the present invention provides a system that facilitates adjusting the wavelengths of lasers via temperature control. This system includes a chip with an active face upon which active circuitry and signal pads reside. A thermal-control mechanism provides localized thermal control of two lasers mounted upon the active face of the chip. By individually controlling the temperature of the lasers, the thermal-control mechanism controls the wavelengths emitted by each respective laser. By creating a temperature gradient that causes a temperature difference between two or more lasers, the system can cause the lasers to emit different wavelengths.

Abstract: A heat spreader for an LED can include a thermally conductive and optically transparent member. The bottom side of the heat spreader can be configured to attach to a light emitting side of the LED. The top and/or bottom surface of the heat spreader can have a phosphor layer formed thereon. The heat spreader can be configured to conduct heat from the LED to a package. The heat spreader can be configured to conduct heat from the phosphors to the package. By facilitating the removal of heat from the LED and phosphors, more current can be used to drive the LED. The use of more current facilitates the construction of a brighter LED, which can be used in applications such as flashlights, displays, and general illumination. By facilitating the removal of heat from the phosphors, desired colors can be better provided.

Abstract: When environmental temperature becomes low, the quantity of light of the backward output light irradiated onto a light absorber formed on a mount over which a chip is mounted, is increased by a light quantity adjuster, to increase the optical absorption by the light absorber, thereby raising its temperature. As a result, the temperature of the chip on the mount rises, thereby enabling to substantially narrow a temperature range on a low temperature side. Accordingly, an optical device with low power consumption that can satisfy characteristics required for signal transmission at a required rate over a wide temperature range can be provided.

Abstract: A laser diode structure that includes two different insulator layers, one to maintain good optical confinement, typically located at the sides of the laser ridge, and another to improve the heat dissipation properties, typically located on the etched surfaces away from the ridge.

Abstract: A light emitting apparatus includes a surface emitting laser and a ceramic package. The surface emitting laser has a common electrode on the back surface thereof and is mounted on the ceramic package via the common electrode. The common electrode of the surface emitting laser is electrically connected to a mount portion of the ceramic package. The mount portion is electrically connected to a back-surface electrode on the back surface of the ceramic package. The mount portion is also thermally connected to a back-surface heat-dissipating electrode on the back surface of the ceramic package via a penetrating electrode that penetrates the ceramic package. The surface emitting laser is spaced apart from the penetrating electrode in order to prevent inclination in light-emitted direction. The back-surface heat-dissipating electrode prevents destruction of a soldered portion when the light emitting apparatus is mounted on a substrate by soldering.

Abstract: A submount for a semiconductor laser. The submount has a layer of silicon carbide (SiC) and a layer of aluminum nitride (AlN) deposited on the layer of SiC. The submount is bonded to the InP-based laser by a hard solder applied to the AlN layer. Preferably, the thickness of the AlN layer is ten to twenty microns, the thickness of the SiC layer is two hundred fifty microns, and the solder is a gold-tin (AuSn) eutectic. The semiconductor laser may be a quantum cascade laser (QCL). Similar combinations of submount materials can be found for other semiconductor laser material systems and types.

Abstract: A circuit controlling the gain of an amplifier in an optical transmitter used for optical communication, including a detection circuit for measuring the power of the RF input to a laser; a gain controller or controlling a gain of an amplifier, and a switch connected to the gain controller, wherein the gain controller is adapted, in response to an activation of a switch, to: (i) automatically vary gain of the amplifier, and (ii) set the gain of the amplifier at a level corresponding to a reduction in the noise and/or distortion associated with the transmitter.

Abstract: A laser diode package assembly includes a reservoir filled with a fusible metal in close proximity to a laser diode. The fusible metal absorbs heat from the laser diode and undergoes a phase change from solid to liquid during the operation of the laser. The metal absorbs heat during the phase transition. Once the laser diode is turned off, the liquid metal cools off and resolidifies. The reservoir is designed such that that the liquid metal does not leave the reservoir even when in liquid state. The laser diode assembly further includes a lid with one or more fin structures that extend into the reservoir and are in contact with the metal in the reservoir.

Abstract: A wavelength conversion laser light source includes: an element temperature switching section that switches a temperature of the wavelength conversion element according to a harmonic wave output value as set in an output setting device, and the element temperature switching section for switching a temperature of a wavelength conversion element according to a harmonic wave output level as set in the output setting device, wherein the element temperature switch section includes an element temperature holding section that holds the wavelength conversion element at the temperature as switched by the element temperature switching section.

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. 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: 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: The present invention relates to a nitride semiconductor laser device having a structure in which two or more of nitride semiconductor laser elements, having at least a first electrode on a first main surface of a first conductive type conductive substrate, having at least a first conductive type nitride semiconductor layer, an active layer, a second conductive type nitride semiconductor layer, and a second electrode on a second main surface of the conductive substrate, and having a stripe-waveguide structure parallel to the first main surface, are arranged in a direction parallel to the first main surface and a direction perpendicular to the direction of light that is emitted from the stripe waveguide structure in the nitride semiconductor laser device, and the first sub-mount and the first electrode of the nitride semiconductor laser element are electrically and heat-conductively connected, and the second sub-mount and the second electrode of the nitride semiconductor laser element are electrically and heat

Abstract: An optical pumping structure for lasers includes: an active medium in the form of a cylindrical rod with a circular cross-section, said rod being inserted at its ends into two rings made of a thermally conductive material; at least three stacks of pumping diode strips arranged in the form of a star around the rod; and a support temperature-regulated by a Peltier-effect module. The rings are in contact with the support, and a stack of diodes, called bottom stack, being situated between the rod and the support, and the structure comprises, for each other stack, a thermal conduction block forming a support for said stack, these blocks being mounted on the cooled support and not being in contact with one another or with the rings.

Abstract: A system for use in identifying one of an unmanned ground vehicle and an unmanned aerial vehicle includes a signal emitter associated with the unmanned vehicle. The signal emitter includes at least one quantum cascade laser. The signal emitter emits a signal having a wavelength between approximately 2 ?m and approximately 30 ?m, and the signal is detectable to identify the unmanned vehicle as friendly at a distance from the signal emitter greater than approximately 1 meter.

Abstract: A weapon system includes a weapon system illuminator laser system and one or more optical fibers. The weapon system illuminator laser system can produce one or more illuminator laser beams to illuminate at least one object outside the weapon system without destroying the object. The weapon system illuminator laser system is located at a first location within the weapon system. The object, or a second object associated with the object, is to be destroyed or damaged by energy. The one or more optical fibers are configured to transport the one or more illuminator laser beams from the first location to a second location within the weapon system. The one or more optical fibers can provide beam containment and beamwalk maintenance in the presence of mechanical or thermal disturbances. The one or more optical fibers and the weapon system illuminator laser system can withstand mechanical or thermal disturbances.

Abstract: An optical transmission circuit includes a light emitting device (10) having different temperature characteristics at low temperature and high temperature (e.g., a VCSEL (Vertical Cavity Surface Emitting Laser), differential switch transistors (M1, M2) for driving the light emitting device (10), the differential switch transistors having sources connected to each other and drains connected to the light emitting device (10) and a power supply, respectively, a bias current source (11) for causing a bias current to flow, a modulated current source (12) for causing a modulated current to flow, and a temperature compensation current source (20) for controlling currents of the bias current source (11) and the modulated current source (12) so as to compensate for both temperature characteristics at low temperature and temperature characteristics at high temperature of the light emitting device (10).

Abstract: Methods and systems are disclosed for cooling a laser, such as a high average power (HAP) solid state laser (SSL). A coolant that has been heated from previous use can be conditioned by transferring heat from the coolant to a phase change medium. The conditioned coolant can then be re-used to cool the laser. In this manner, a low cost, lightweight, compact cooling system that generates comparatively quiescent flow at comparatively high flow rates can be provided.

Abstract: A laser diode package assembly includes a reservoir filled with a fusible metal in close proximity to a laser diode. The fusible metal absorbs heat from the laser diode and undergoes a phase change from solid to liquid during the operation of the laser. The metal absorbs heat during the phase transition. Once the laser diode is turned off, the liquid metal cools off and resolidifies. The reservoir is designed such that that the liquid metal does not leave the reservoir even when in liquid state. The laser diode assembly further includes a lid with one or more fin structures that extend into the reservoir and are in contact with the metal in the reservoir.

Abstract: A laser diode structure for generating a collimated or divergent laser beam, preferably for application in gas detection, with a laser diode arranged in a closed housing, with the housing comprising a housing bottom, an exit window, electrical connections, a temperature control device for the laser diode, and an optical element for influencing the laser beam. The temperature control device carrying the laser diode is arranged on the housing bottom and the optical element is positioned at a distance from the laser diode. The invention proposes an electrically controllable power device for the cyclic alteration of the position and/or alignment of the optical element in relation to the laser diode so that the optical path length for the laser beam in the housing changes periodically.

Abstract: An optical device includes an optical material comprising active dopant ions and absorber dopant ions spaced apart from the active dopant ions. The active dopant ions are provided to absorb a first radiation and convert a portion of the first radiation into sensible heat. A concentration profile of the absorber dopant ions is selected to absorb a second radiation different from the first radiation and optionally the first radiation in at least one direction of the optical material so as to control a refractive index profile in the at least one direction of the optical material.

Abstract: In a coarse wavelength division multiplexing (CWDM) optical transmission system, a distributed feedback (DFB) laser is tuned so that the peak reflection of the grating overlaps with the gain range of the DFB laser. The diffraction grating is tuned so that the peak is positioned on the long wavelength end of the gain spectrum at a selected temperature. The optical transmission system operates in an environment having a wide temperature range (i.e., about ?40° C. to about 85° C.). Heat is applied to the laser and as the laser temperature increases, the gain range overtakes the grating peak. When the gain range and the grating peak overlap at increased laser temperature, laser output is improved.

Abstract: A high gain solid-state laser apparatus capable of generating short-pulse terahertz waves with high efficiency is provided. The apparatus includes laser gain media 1 and an optical switch 3 that entraps seed light from a laser oscillator into the apparatus and outputs amplified laser light pulses from the apparatus. In the apparatus, ytterbium-doped lutetium lithium tetrafluoride (LuLiF4) crystal that is cooled below the liquid-nitrogen temperature is used as the laser gain media.

Abstract: Designs and processes for thermally stabilizing a vertical cavity surface emitting laser (vcsel) in a chip-scale atomic clock are provided. In one embodiment, a Chip-Scale Atomic Clock includes: a vertical cavity surface emitting laser (vcsel); a heater block coupled to a base of the vcsel; a photo detector; a vapor cell, wherein the vapor cell includes a chamber that defines at least part of an optical path for laser light between the vcsel and the photo detector; and an iso-thermal cage surrounding the vcsel on all sides, the iso-thermal cage coupled to the heater block via a thermally conductive path.

Abstract: A laser device having a wave emission within a frequency range of 0.5 to 5 THz, includes a semiconductor heterostructure having a cylindrical form with a circular cross-section and including: a first optically nonlinear semiconductor material layer including an emitting medium configured to emit at least two optical whispering gallery modes belonging to the near-infrared spectrum, the two whispering gallery modes being confined within the first layer and enabling the generation, within the first layer, of radiation within an electromagnetic whispering gallery mode having a frequency of 0.

Abstract: A high-powered diffraction limited diode pumped solid-state source optically end pumps a compact, widely tunable solid state material. Imaging of the collimated pump beam into the tunable medium produces ideal volumetric overlap producing high conversion efficiencies. Fully integrated pump source provides pump energy at or near the peak absorption wavelength. Birefringent elements placed intracavity are used for linewidth narrowing and tuning of the laser wavelength. Tunable active medium is placed in linear cavity arrangement utilizing a confocal or hemispherical arrangement. Mode waist is minimized in crystal such that there is optimal overlap with pump source while simultaneously maximizing extraction efficiency.

Abstract: A cut-out portion of a ground conductor is located in a region where a header faces a flexible board from the junction of a signal pin and a signal line and faces the signal line. The size of the cut-out portion is determined so that the impedance of the signal pin is matched to the impedance of the signal line.

Abstract: Systems and methods for controlling a thermoelectric cooler (TEC) in an optical transceiver. A TEC system includes a processor that interacts with a power supply and a TEC controller to prevent inrush current. The power supply is switched by the processor and turned on only at a particular time. The power supply has a relatively large time constant such that it ramps slowly to its full value. In the meantime, the processor and TEC controller cause the temperature to ramp to a target value by repeatedly incrementing or decrementing a target value over time and by controlling when the maximum available voltage can be applied to the TEC.

Abstract: A semiconductor laser device includes: a semiconductor laser; a carrier that has a carrier side face facing with a longitudinal direction of the semiconductor laser, has a carrier edge area, and has a first bonding area that is the closest to a first end of the semiconductor laser and a second bonding area that is the closet to a second end of the semiconductor laser; a first thermal conduction portion that has a first thermal resistance and couples between the first bonding area and an outer connection terminal; and a second thermal conduction portion that has a second thermal resistance smaller than the first thermal resistance and couples between the second bonding area and an outer connection terminal, wherein the first end side of the semiconductor laser is closer to the carrier side face than the second end side of the semiconductor laser.

Abstract: A laser light source includes: a laser array in which plural emitters are arranged; and a submount having first and second surfaces facing in opposite directions. The laser array is provided on the first surface. A distance between the first surface and the second surface of the submount varies along an array arrangement direction of the laser array.

Abstract: A laser resonator comprises a cylindrical gain medium, a cooling system and a coupling member. The cylindrical gain medium comprises a central axis, an outer side surface, two opposing end faces and a first depression in the outer side surface. The cooling system comprises a cooling jacket disposed around the gain medium that defines a cooling cavity, in which cooling fluid is guided over the side surface of the gain medium. In one embodiment, the cooling jacket comprises a second depression. The coupling member is received within the first and second depressions. Movement of the first depression along the central axis relative to the cooling jacket is restricted by the coupling member.

Abstract: A laser light source apparatus includes a laser light source; a heat exchanger that includes a plurality of cooling fins and that cools the laser light source; a driving circuit that drives the laser light source; a housing including an intake port and an exhaust port; and an air-cooling fan that is attached to the housing and that discharges air taken in from the intake port to the exhaust port. The cooling fins are arranged at a position opposed to the intake port to be stacked up on each other at predetermined intervals and a pitch between the cooling fins is equal to or less than a minimum width of the intake port.