Abstract: A first contact surface of a semiconductor laser chip can be formed to a target surface roughness selected to have a maximum peak to valley height that is substantially smaller than a barrier layer thickness. A barrier layer that includes a non-metallic, electrically-conducting compound and that has the barrier layer thickness can be applied to the first contact surface, and the semiconductor laser chip can be soldered to a carrier mounting along the first contact surface using a solder composition by heating the soldering composition to less than a threshold temperature at which dissolution of the barrier layer into the soldering composition occurs. Related systems, methods, articles of manufacture, and the like are also described.

Abstract: A vortex laser generation device in a degenerate cavity with a spiral phase element and a vortex laser generation method are provided. The vortex laser generation device has a degenerate cavity, and the degenerate cavity has a resonator mirror, a gain medium, an optical element, and an output coupler. The off-axis beams are formed in multiple pass transverse modes to resonate by disposing an optical element in the degenerate cavity, so that a vortex laser with orbital angular momentum can be generated.

Abstract: The present invention provides a rotating chalcogenide gain media ring to provide un-precedented power generation with minimal thermal lensing for CW lasing in the mid-IR spectrum.

Abstract: A semiconductor laser resonator configured to generate a laser beam includes a gain medium layer including a semiconductor material and comprising at least one protrusion formed by at least one trench to protrude in an upper portion of the gain medium layer. In the semiconductor laser resonator, the at least one protrusion is configured to confine the laser beam as a standing wave in the at least one protrusion.

Abstract: A light-emitting element module includes: a Peltier device; a light-emitting element that is disposed on the Peltier device; and a package that accommodates the Peltier device and the light-emitting element, the package including a base on which the Peltier device is disposed and a lid joined to the base and. When Ts is external temperature of the package, Tv is temperature of the light-emitting element, Tc1 is temperature of the base, and Tc2 is temperature of the lid, Ts<Tc2<Tc1 is satisfied in a case of Tv<Ts.

Abstract: A sensor unit (10) for detecting a gas is configured with a pressure-tight measuring channel (11), with a gas inlet (12) for introducing the gas into the measuring channel, with a gas outlet (13) for removing the gas from the measuring channel, and with a pump unit (14) for evacuating the measuring channel. The measuring channel has a gas sensor (15) for detecting the gas and a heating unit (16) for heating the gas sensor. The sensor unit (10) is configured to be operated in a measuring mode and in a regeneration mode. The measuring channel (11) is evacuated and the gas sensor (15) is heated in the regeneration mode.

Abstract: An optical transmitter includes a reflective semiconductor optical amplifier (RSOA) coupled to an input end of a first optical waveguide. An end of the first optical waveguide provides a transmitter output for the optical transmitter. Moreover, a section of the first optical waveguide between the input end and the output end is optically coupled to a ring modulator that modulates an optical signal based on an electrical input signal. A passive ring filter (or a 1×N silicon-photonic switch and a bank of band reflectors) is connected to provide a mirror that reflects light received from the second optical waveguide back toward the RSOA to form a lasing cavity. Moreover, the ring modulator and the passive ring filter have different sizes, which causes a Vernier effect that provides a large wavelength tuning range for the lasing cavity in response to tuning the ring modulator and the passive ring filter.

Abstract: A method for the recovery of energy from a laser machining system and a device for performing the same, in which the method includes operating the laser machining system and generating thermal energy having a maximum temperature Tmax, removing at least a portion of the thermal energy, and recirculating the at least a portion of the thermal energy to the laser machining system.

Abstract: A solution for packaging a two terminal device, such as a light emitting diode, is provided. In one embodiment, a method of packaging a two terminal device includes: patterning a metal sheet to include a plurality of openings; bonding at least one two terminal device to the metal sheet, wherein a first opening corresponds to a distance between a first contact and a second contact of the at least one two terminal device; and cutting the metal sheet around each of the least one two terminal device, wherein the metal sheet forms a first electrode to the first contact and a second electrode to the second contact.

Abstract: An energy conversion device comprises an apparatus and a method for employing energy from an electron- and, optionally, photon-containing energy wave that is induced in one or more aggregated molecular ensembles. Emission is stimulated from the ensembles by a wide variety of energy inputs, and energy derived from this electron and/or photon energy wave is useful for modulation of signals in circuits; performing chemical reduction reactions; and performing as an energy conversion device, e.g., as a photovoltaic energy converter. Although differing from a laser by virtue its production of, inter alia, a charge transfer rather than merely light, the device of the invention can be employed in virtually all of the same fields in which a laser is utilized.

Abstract: Embodiments of the present invention are directed to heat transfer arrays, cold plates including heat transfer arrays along with inlets and outlets, and thermal management systems including cold-plates, pumps and heat exchangers. These devices and systems may be used to provide thermal management or cooling of semiconductor devices and particularly such devices that produce high heat concentrations. The heat transfer arrays may include microjets, microchannels, fins, and even integrated microjets and fins. Other embodiments of the invention are directed to heat spreaders (e.g. heat pipes or vapor chambers) that provide enhanced thermal management via enhanced wicking structures and/or vapor creation and flow structures. Other embodiments provide enhanced methods for making such arrays and spreaders.

Abstract: Laser with extended mode-hop free spectral tuning ranges and methods for manufacturing such lasers are disclosed. In an embodiment the method includes providing a light emitting device, the light emitting device comprising a gain region and a first wavelength selection region and mounting the light emitting device on a thermally conductive carrier such that the gain region is mounted on a first carrier surface and the first wavelength selection region is arranged over and spaced apart from a second carrier surface.

Abstract: Optical telecommunications devices, systems, and methods. In some implementations, an optical networking unit (ONU) includes a multi-rate receiver having an operating bandwidth that is selected operationally based on physical layer characteristics of received signals and information received from a MAC. The ONU can also include an upstream laser circuit having an output impedance that differs from a characteristic impedance of a system in which the laser circuit is implemented. The ONU can also include a decision feedback equalizer (DFE) having at least one tap weight that is fixed to facilitate convergence of the DFE when signals received by the DFE would otherwise fail to meet characteristics required for DFE convergence.

Abstract: A laser processing system able to realize both reduction of the power consumption and shortening of the cycle time. The laser processing system is provided with a laser oscillator, a laser processing machine which has a movement mechanism which makes the irradiation position of the laser light on the workpiece move, a mode switching part which switches an operation mode of the laser oscillator between a standard-standby mode and an energy saving mode, a movement controller controlling the movement mechanism so as to place the irradiation position at a process start point placed at a non-product region of the workpiece, and a switching controller controlling the mode switching part to switch the operation mode from the energy saving mode to the standard-standby mode when placing the irradiation position at the process start point.

Abstract: The present invention provides a semiconductor laser device for improving temperature characteristics of waveguide structures and realizing stable light emitting patterns and high output, and a method for making the same. The semiconductor laser device (1) comprises: an n-type clad layer (5) laminated on a substrate (2); an active layer (6) laminated on the n-type clad layer (5); a p-type clad layer (7) laminated on the active layer (6); and a plurality of waveguide structures (8) formed on the p-type clad layer (7) and having a ridge of a horn shape in top view. In this configuration, a divider (29) is formed between adjacent waveguide structures (8), and the divider (29) comprises: a groove (30) dividing the active layer (6); and a heat dissipation material (34) filled in the groove (30) and having a thermal conductivity higher than a thermal conductivity of a semiconductor layer (4).

Abstract: In accordance with embodiments of the present disclosure, a blower module assembly may include a housing, a blower mechanically coupled to the housing, and an airflow guide mechanically coupled between the housing and the blower. The blower may be mechanically coupled to the housing, may have an intake and an exhaust, and may be configured to move air from the intake to the exhaust. The airflow guide may be mechanically coupled between the housing and the blower, may have a solid region and a plenum region such that the border between the solid region and the plenum region is defined by a portion of an arcuate cylinder. The housing, the blower, and the airflow guide may be arranged such that a plenum is defined by surfaces of the housing, the blower, and the portion of the arcuate cylinder, the plenum adjacent to the intake.

Abstract: A two-dimensional VCSEL array may include a VCSEL array including a VCSELs arranged in a two dimensional matrix forming a monolithic structure, a light-emitting surface, and a rear surface, first metal contacts provided on the light-emitting surface; and second metal contacts provided on the rear surface. The VCSELs may be arranged in first lines in a first direction and second lines in a second direction non-parallel to the first direction. Each of the first metal contacts may be electrically connected to each VCSEL of a corresponding first line. Each of the plurality of second metal contacts may be electrically connected to each VCSEL of a corresponding second line. The first metal contacts and second metal contacts may be arranged such that each combination of a first metal contact and a second metal contact is electrically connected to one VSCEL.

Abstract: A laser oscillation cooling device (100) includes a light emitting section (1) that emits laser excitation light (Z1), a laser excitation section (2) that excites the laser excitation light (Z1) to emit laser light (Z2) and has a heat generating region (S) where heat is locally generated, a storage tank (3) capable of storing an extremely low temperature liquid (L), a pressurizing section (31) that brings the extremely low temperature liquid (L) into a sub-cool state by pressurizing the inside of the storage tank (3), and a jetting supply section (4) that removes heat from the laser excitation section (2) by jetting the extremely low temperature liquid (L) in the sub-cool state from a plurality of jet ports arrayed in a two-dimensional manner to the laser excitation section (2).

Abstract: Embodiments of the present disclosure may relate to a hybrid silicon distributed feed-back (DFB) laser, wherein light is to propagate through the DFB laser along a length of the DFB laser. The DFB laser may include a mesa with a current channel that extends from the first side of the mesa to the second side of the mesa. At a first location along the length of the DFB laser, the current channel may have a first width and/or the mesa may have a second width. At a second location along the length of the DFB laser, the current channel may have a third width and/or the mesa may have a fourth width as measured in a direction perpendicular to the length of the DFB laser. Other embodiments may be described and/or claimed.

Abstract: A sealable laser diode heat sink module for a laser diode includes an anode assembly and a cathode assembly having a cathode base and a cathode connector plate. The anode assembly includes an anode base configured to house the laser diode and the cathode base within a sealable cavity recessed into the anode base. The anode base has a cathode base opening configured to receive the cathode connector plate. An anode connector plate extends from the anode base. An anode current path passes through the laser diode and the anode connector plate via direct connections through the anode base. A cathode current path passes through the cathode connector plate passes via direct connections through the cathode base. The anode base is configured to dissipate heat from the laser diode.

Abstract: A tunable laser has a first binary super grating (BSG), a second BSG, and a phase adjuster. The first BSG, the second BSG, and the phase adjuster are optically tuned by changing temperatures of respective heating elements. The tunable laser also includes three temperature sensors, a first sensor to measure the temperature of the first BSG; a second sensor to measure the temperature of the second BSG, and a third sensor to measure the temperature of the phase adjuster. A lasing frequency is determined by a set of values of the three temperature sensors. In some embodiments, instead of a third temperature sensor, a pilot tone is applied to the phase adjuster to lock to a maximum of an aligned pair of peaks.

Abstract: A modulator driver circuit for providing a drive voltage to an electro-absorption modulator, such a Franz-Keldysh modulator, or to a micro-ring modulator, and an optical transmitter including such driver circuit, where said driver circuit includes a differential amplifier and at least one differential branch of the differential amplifier being provided with a voltage offset. This provides for a bias voltage being adjustable within the driver circuit itself. Preferably, the differential amplifier is arranged for supplying drive voltage to two complementary driver outputs providing a reverse bias relative to the modulator. In one embodiment, the differential amplifier includes a cascode in the differential branch not being provided with the voltage offset.

Abstract: A projection type display apparatus includes: a semiconductor laser element that outputs laser light based on supply of current; a digital mirror device (DMD) that modulates the light output from the semiconductor laser element and emits the modulated light; a projection lens that projects the incident light via the DMD; a drive unit that drives the semiconductor laser element and includes a current detection unit for detecting the current value of the current flowing through the semiconductor laser element; and a controller that, when the current value detected by the current detection unit becomes greater than a first threshold, controls driving of the DMD so that the light output from the DMD will not be incident on the projection lens, and when the current value detected becomes greater than a second threshold greater than the first threshold, causes the drive unit to cut off the supply of current.

Abstract: A thermal management system for removing excess heat from a heat source includes a condenser and an evaporator fluidly connected together within a cooling loop. A phase change material is positioned within the condenser. The phase change material is configured to melt with a liquid coolant warmed by the evaporator. The phase change material is also configured solidify with the liquid coolant cooled by the condenser to temperatures below the melting point.

Abstract: In one embodiment the table pointed to by visibility samples in Degradation Coverage-Based Anti-Aliasing is split up so that more values can fit (but each value uses fewer bits). This way, more values can be represented in a pixel, and this leads to better image quality in some embodiments. This also opens up the possibility of using as few as two values per pixel, whereas the CSAA uses four or more. Hence, this also saves bandwidth and therefore, also reduces power consumption in some embodiments.

Abstract: Disclosed herein is a technology of effectively interrupting light reflected from a wavelength selective filter so as not to be fed back to a laser diode chip in a semiconductor laser package having a function of adjusting a relative intensity ratio of a signal of “1” and a signal of “0” using an optical filter. Since an optical interruption device according to the present invention may effectively interrupt a light feedback to the laser diode chip by adjusting characteristics of a 45 degree partial reflection mirror in an existing TO-can type laser device having the 45 degree partial reflection mirror and additionally disposing one ?/4 waveplate, unlike an optical isolator according to the related art using an existing Faraday rotator, the signals of “1” and “0” may be effectively adjusted in a TO-can type laser device having a small volume, thereby improving a function of communication.

Abstract: A laser oscillation cooling device (100) is provided with a light emitting section (1) that emits laser excitation light (Z1), a laser excitation section (2) that excites the laser excitation light (Z1) to emit laser light (Z2) and locally generates heat, a storage tank (3) capable of storing an extremely low temperature liquid (L), a pressurizing section (31) that brings extremely low temperature liquid (L) into a sub-cool state by pressurizing the inside of the storage tank (3), and a jetting supply section (4) that removes heat from the laser excitation section (2) by jetting the extremely low temperature liquid (L) in the sub-cool state to the laser excitation section (2).

Abstract: A compact laser is provided for in accordance with an exemplary embodiment in the present disclosure includes a compact resonator structure using a non-planar geometry of bulk components. The laser includes a preferred rotational direction of lasing modes and employs bulk components for establishing the preferred rotational direction of lasing modes within resonator. In some embodiments, the preferred rotational direction of lasing modes is established using a reflective element that is outside the resonator structure. In some embodiments, the reflective element induces polarization shifts in the reflected light that are compensated for by a wave plate, which may be outside the resonator structure.

Abstract: A heat sink for cooling a laser gain medium includes a coolant channel, an inlet pore, an outlet pore, and a thermal optical interface (TOI) channel. The coolant channel is configured to receive a coolant for removing heat from the heat sink. The TOI channel is coupled to the coolant channel by the inlet pore and the outlet pore. The TOI channel is configured to receive a portion of the coolant through the inlet pore. The received portion forms an ultra-thin liquid TOI. The TOI channel is further configured to return a portion of the TOI through the outlet pore to the coolant channel.

Abstract: A package including optical components has one or more structures with optical input or optical output. An optical interconnection optically connects to the optical input or optical output of the structure(s). A component is provided in which the optical interconnection and the optical input or optical output of the structure(s) are embedded. The component is made of a first material and the optical interconnection of a second material. The first and second materials are chemically identical. The first material has a first primary and/or secondary structure and the second material has a second primary and/or secondary structure. The first primary and/or secondary structure is different from the second primary and/or secondary structure. The refractive indices of the component and of the optical interconnection differ from each other by at least 0.0004 at 850 nm, 1,310 nm, and 1,550 nm, respectively. The optical interconnection is mechanically fixed by the component.

Abstract: The invention provides a laser light emitting device, which comprises a laser light emitter for emitting a pump light, a resonator for emitting a laser beam by oscillating and amplifying the pump light and a multi-mode fiber for guiding the pump light emitted from the laser light emitter to the resonator, wherein a mode scrambler is provided on the multi-mode fiber, the pump light propagating the multi-mode fiber is stirred and a light intensity distribution is unified by the mode scrambler, and the pump light is entered to the resonator.

Abstract: An optical receiver receives a wavelength multiplexed optical signal including wavelength channels. A superimposition signal is superimposed by frequency modulation on each of the wavelength channels. The optical receiver includes: an optical filter that filters the wavelength multiplexed optical signal; a filter controller that controls a wavelength of a transmission band of the optical filter; a photo detector that generates an intensity signal representing a change in the intensity of an output light of the optical filter; an signal detector that detects, according to the intensity signal, a superimposition signal superimposed on a specified wavelength channel. The filter controller controls the wavelength of the transmission band so that the amplitude of the intensity signal is larger, and then controls the wavelength of the transmission band so that the number of errors in the superimposition signal detected by the signal detector is reduced.

Abstract: In the prior art, tunable lasers utilizing silicon-based tunable ring filters and III-V semiconductor-based gain regions required the heterogeneous integration of independently formed silicon and III-V semiconductor based optical elements, resulting in large optical devices requiring a complex manufacturing process (e.g., airtight packaging to couple the devices formed on different substrates, precise alignment for the elements, etc.). Embodiments of the invention eliminate the need for bulk optical elements and hermetic packaging, via the use of hybridized III-V/silicon gain regions and silicon optical components, such as silicon wavelength filters and silicon wavelength references, thereby reducing the size and manufacturing complexity of tunable lasing devices.

Abstract: An optical module includes a package, a substrate, a lead pin, and a ground pattern. The substrate is accommodated in the package, includes a signal line pattern that transmits an electric signal, extends toward a side wall of the package beyond an end of the signal line pattern, and has a through hole between the end of the signal line pattern and the side wall of the package. The lead pin is inserted into the through hole in the substrate and inputs the electric signal to the end of the signal line pattern. The ground pattern is provided in at least a part of regions surrounding the through hole on the substrate.

Abstract: A flip chip type laser diode includes a removable substrate, a first semiconductor layer, an emitting layer, a second semiconductor layer, at least one current conducting layer, a patterned insulating layer, at least one first electrode and a second electrode. The first semiconductor layer is disposed on the removable substrate. The emitting layer is disposed on a part of the first semiconductor layer. The second semiconductor layer is disposed on the emitting layer and forms a ridge mesa. The current conducting layer is disposed on a part of the first semiconductor layer. The patterned insulating layer covers the first semiconductor layer, the emitting layer, a part of the second semiconductor layer and a part of the current conducting layer. The first electrode and the second electrode are disposed on areas of the current conducting layer and the second semiconductor layer which are not covered by the patterned insulating layer.

Abstract: For determining whether a configuration of an optical transmission interface of a first device has to be adjusted for transmitting optical signals to a second device via an optical band-pass filter, the second device having an optical reception interface configured to enable receiving optical signals output by said optical band-pass filter and transmitted by the first device on a carrier wavelength when said carrier wavelength is comprised in the passband of the optical band-pass filter, said carrier wavelength and/or said passband of the optical band-pass filter being a priori unknown, a monitoring device performs: monitoring an evolution of a difference level between codewords received by the second device via said optical signals and corresponding codewords transmitted by the first device; and determining whether the configuration of the optical transmission interface of the first device has to be adjusted, on the basis of said monitoring.

Abstract: The present disclosure discusses an improved optical transceiver. The optical transceiver of the present disclosure includes an optical transmitter and an optical receiver that are spatially separated. In some implementations, the optical receiver and optical transmitter are staggered from one another. Each of the optical receiver and the optical transmitter and housed within a separate optical lens. In some implementations, the separation of the components reduces mechanical, thermal, and electrical cross talk between the optical transmitter and the optical receiver. The separation of the components can also ease the constraints of the optical alignment between the optical transmitter and the optical receiver and each of their respective lenses.

Abstract: A carbon dioxide waveguide-laser includes an elongated resonator unit and an elongated power-supply unit. The resonator and power-supply units are spaced by a cooling unit including a plurality of longitudinally extending, spaced-apart fins, with fans arranged to drive air through the spaces between the fins.

Abstract: A gas laser oscillator according to the present invention comprises a resonator unit, a heat exchanger through which a fluid exchanging heat with a laser gas flows, a chiller for cooling the fluid in the heat exchanger and supplying the fluid to the heat exchanger, and a heat transfer device for transferring heat of the fluid to the resonator unit. The gas laser oscillator further comprises a first flow path for supplying the fluid used for cooling the laser gas in the heat exchanger to the heat transfer device, a second flow path for supplying the fluid cooled by the chiller to the heat transfer device prior to supplying the fluid to the heat exchanger, and a switching valve for switching either one of a first flow path and a second flow path.

Abstract: A semiconductor laser device includes a semiconductor laser element; a mounting body on which the semiconductor laser element is mounted; a base having a recess in which the mounting body is mounted and a through hole that penetrates a part of a bottom of the recess; and an embedded member disposed within the through hole. An uppermost surface of the embedded member is joined to a lowermost surface of the mounting body and a lowermost surface of the embedded member is positioned higher than a lowermost surface of the base.

Abstract: The present invention is directed to a package including optical components, comprising: (i) at least one structure, the structure having at least one optical input or output, (ii) at least one optical interconnection, optically connected to the at least one optical input or output, and (iii) a component in which the at least one optical interconnection and the at least one optical input or output is embedded, wherein (a) the component (iii) embedding the at least one optical interconnection and the at least one optical input or output and the at least one optical interconnection (ii) are made from a chemically identical material, wherein the material of the at least one optical interconnection has a different primary and/or secondary structure, compared to the material of the component embedding the at least one optical interconnection and the at least one optical input or output, (b) the component (iii) embedding the at least one optical interconnection and the at least one optical input or output and the a

Abstract: A light emitting diode (LED) linear light modulator with temperature compensation includes a comparing module, a timing processing module, an LED module and a temperature compensating current control module. The comparing module compares an analog input signal with a triangular wave sampling signal to generate a pulse width modulation (PWM) signal. The PWM signal is inputted into the timing processing module and converted to a digital signal. The temperature compensating current control module, electrically connected to the LED module and the timing processing module, includes a plurality of low-temperature correlated linear current units and a switching switch, and controls a current amount passing through the LED module to generate a low-temperature correlated linear current. Thus, the color temperature of an LED is prevented from drifting with a change in the ambient temperature.

Abstract: A TOSA can include: a light emitting element; and one or more heating elements thermally coupled to the light emitting element so as to provide a substantially constant heat generation profile and/or temperature profile across the TOSA during a light emitting element dormant period and a light emitting element firing period. The TOSA can include a controller operably coupled with the one or more heating elements so as to control the substantially constant heat generation profile and/or temperature profile. In one aspect, the one or more heating elements can include one or more dedicated heating elements. In one aspect, the one or more of the dedicated heating elements can include a resistor element or coil.

Abstract: A laser diode assembly contains a plurality of laser diode chips packaged closely in a row. Each laser diode chip is bonded on both P-side and N-side to first and second sub-mounts. The sub-mounts are then attached to a cooling carrier, with both bonding surfaces perpendicular to the top surface of the carrier. The direction of laser radiation is parallel to the carrier top surface, and the distance between the top of the active area of the laser diode chip and the carrier is preferably in a range of half a pitch between individual laser sources packaged in a row or preferably in a range of 0.2 mm to 1 mm to allow efficient cooling for high power operation. The sub-mounts may be electrically conductive, or they may be of insulating material at least partially covered with a conducting layer. A laser diode chip is bonded uniquely to a set of sub-mounts or may share a sub-mount with another laser diode chip.

Abstract: A laser transmitter includes a heat sink, a laser disposed on the heat sink, and a connection apparatus. The connection apparatus includes: a lower substrate and an upper substrate disposed on the lower substrate. An upper surface of the lower substrate is disposed with a first conductor, and a lower surface thereof is disposed with a second conductor. The upper substrate has an upper surface disposed with a third conductor, where the third conductor is connected to the second conductor. The heat sink is disposed on a side of the lower substrate that is close to an end of the first conductor. The laser is connected to an end of the first conductor that is close to the heat sink.

Abstract: A method for producing optical semiconductor devices includes: forming a stacked semiconductor layer on a device substrate to provide an epitaxial substrate having a size corresponding to a section arrangement; forming, on the epitaxial substrate, a mask having a pattern for a semiconductor mesa and for a trench of at least one optical semiconductor device, a width of the trench in the pattern being determined according to a trench width map in which trench width is based upon an in-plane distribution of the thickness of a resin layer of the at least one device, and upon a correlation between the thickness of the resin layer and the trench width; forming a trench structure including the semiconductor mesa and the trench by etching the stacked semiconductor layer using the mask; forming a resin layer on the trench structure; and forming an opening on the semiconductor mesa by etching the resin layer.

Abstract: A cooling arrangement for cooling laser gas for a gas laser includes a first cooling circuit having a first cooling assembly and a first heat exchanger for cooling laser gas which flows from a fan to a resonator of the gas laser, and a second cooling circuit which is independent of the first and which has a second cooling assembly and a second heat exchanger for cooling laser gas which flows from the resonator to the fan. The second cooling circuit has at least one additional heat exchanger for additionally cooling the laser gas which flows from the fan to the resonator.

Abstract: A laser for generating deep ultra-violet (DUV) continuous wave (CW) light includes a second-harmonic generator and a fourth-harmonic generator. The fourth-harmonic generator includes a plurality of mirrors as well as first and second non-linear optical (NLO) crystals. The first NLO crystal generates the light having the fourth harmonic wavelength, and is placed in operative relation to the plurality of mirrors. The second NLO crystal is placed in operative relation to the first NLO crystal such that the light having the second harmonic wavelength passes through both the first and the second NLO crystals. Notably, the second optical axes of the second NLO crystal are rotated about a direction of propagation of the light within the second NLO crystal approximately 90 degrees relative to the first optical axes of the first NLO crystal. The second NLO crystal provides no wavelength conversion.

Abstract: An apparatus for output light with a wavelength tunable function, includes: a semiconductor laser diode (LD) including regions to determine an oscillation wavelength, the regions providing respective diffraction gratings and electrodes to control refractive index of the regions; a temperature controller for mounting the LD thereon to control a temperature of the LD; and a controller configured to vary the refractive index of the regions by providing control signals to the electrodes and another control signal to the temperature controller for varying the temperature of the LD to coincide the oscillation wavelength with a target wavelength.

Abstract: A method and apparatus provide for determining a temperature at a junction of a laser diode when the laser diode is operated in a lasing state that facilitates heat-assisted magnetic recording, comparing the junction temperature and an injection current supplied during the lasing state to stored combinations of junction temperature and injection current, and determining a likelihood of mode hopping occurring for the laser diode during the lasing state based on the comparison to stored combinations of junction temperature and injection current.