Abstract: An assembly for providing a concentrated, vertically stacked array of laser beams from a horizontally offset array of electrically serially-connected metallic microchannel heat sinks each bearing a laser diode bar. The heat sinks are mounted on horizontally offset planes of the manifold which has coolant channels serving adjacent heat sinks that are separated from each to increase the electrical resistance of the fluid path between adjacent ones of said heat sinks. Stepped optical deflectors re-arrange the horizontally emitted laser beams into vertical stack.

Abstract: A solid-state laser system includes a solid-state laser having a laser gain medium and at least one pumping diode. The system also includes a thermal management system capable of placing a coolant in thermal communication with the solid-state laser such that the coolant can carry heat away from the solid-state laser. The thermal management system is then capable of rejecting the heat carried away by the coolant to a fluid at an ambient temperature, where the coolant can be at a temperature between 40° C. and 80° C. when the thermal management system rejects the heat. Advantageously, the thermal management system of the present invention can include reject the heat to a fluid comprising, for example, air or water. As such, the thermal management system does not require separate cooling of the fluid carrying the heat away from the coolant.

Abstract: A method and device for tuning the wavelength of an optoelectronic component arrangement including at least two optoelectronic components. The characteristic wavelength for each optoelectronic component is adjusted using a respective resistance device which is connected between a common voltage/power source and a respective heating device associated with each optoelectronic component. Heating capacity is modified by changing the overall resistance of the respective resistance device (RM) in order to adjust wavelength. The wavelength of semiconductor lasers, filters, wavelength multiplexers and waveguides may be tuned.

Abstract: A photonic device designed with an intermittent absorption profile along a waveguide. The absorption profile is divided into low-absorption and high-absorption segments that are distributed axially in order to decrease the maximum local temperature in the device. The distribution of low-absorption segments can be controlled through techniques such as proton implantation or selective-area quantum well intermixing. The lengths of low-absorption and high-absorption segments can be adjusted to optimize heat dissipation along the device length.

Abstract: A semiconductor laser device has a support body constructed of a disk-shaped section and a columnar body formed in a central portion of this disk-shaped section, one set of leads fit to this support body in an integrated manner, a semiconductor laser element mounted on a reference surface of the columnar body, and a wire for electrically connecting this semiconductor laser element with one of the leads. The disk-shaped section of the support body has an opening therethrough. The one set of leads are inserted through the opening, placed in position, and integrated with the support body via a resin block filling the opening.

Abstract: A diode pumped solid state laser for producing a high aspect ratio beam comprises a diode pumping array (1) on a diode array mount (3) and optical means for imaging a pump light beam onto a substantially asymmetrical spot with a smooth intensity profile. The pump light beam is pumping a laser medium (4). Both the pump and the lasing mode have strong asymmetries. In combination with the right choice of laser medium (4), this results in high power laser performance. The axis of the pump light beam is adjustable by a simple adjusting means (110) to a defined plane or direction relative to a mounting frame (111) of a diode array pumping device (103). The adjusting means (110) compensates small tolerances on mounting of the diode array (1) and/or at least one optical element (2). The adjusting means include at least one wedged window (127). Because of this adjustment the axis of the light beam lies in a defined plane relative to the mounting frame (111) of the pumping device (103).

Abstract: A laser apparatus and method that uses active thermalization of a reflective element to minimize losses and provide wavelength stability. The laser comprises first and second reflectors defining an external cavity, and a compensating member coupled to at least one of the reflectors and configured to thermally position one reflector with respect to the other reflector. The compensating member may be coupled directly to the first reflector and configured to position first reflector with respect to said second reflector. The thermal positioning may be carried out by a thermoelectric controller operatively coupled to the compensating member and configured to thermally adjust the compensating member by heating or cooling thereof. The laser apparatus may comprise a gain medium having first and second output facets and emitting a coherent beam from the first output facet along an optical path.

Abstract: A cooling device for an optical amplifier or oscillator has Peltier elements enclosed in a housing with an optical crystal and extract heat from the optical crystal. The housing is sealed and can contain a desiccant for removing moisture and preventing particle deposition. Alternately, the housing can be evacuated with a vacuum to maintain a clean operating environment. The housing holds a Brewster window at a Brewster angle with an inident laser beam to permit passage of the laser beam. The housing also can be arranged on a platform providing liquid cooling.

Abstract: A method for calibrating a multi-channel laser emitter in an optoelectronic transceiver or an optoelectronic transmitter for a first wavelength includes monitoring the wavelength of optical signals from the laser emitter while varying its temperature as well as other operating conditions, and then storing calibration information in the memory of a microprocessor. The initial values of the calibrating procedure are reset and the calibrating procedure is repeated to obtain calibration information for a next desired wavelength.

Abstract: An optical assembly that can be utilized as a transmitter in a high data rate optical transceiver system is presented. The optical assembly allows a laser driver to be mounted near the laser and allows the laser driver and the laser to utilize a common heat sink. Further, assembly can be performed reliably and quickly to reduce the cost of production of the optical assembly.

Abstract: A method for calibrating a multi-channel laser emitter in an optoelectronic transceiver or an optoelectronic transmitter for a first wavelength includes monitoring the wavelength of optical signals from the laser emitter while varying its temperature as well as other operating conditions, and then storing calibration information in the memory of a microprocessor. The initial values of the calibrating procedure are reset and the calibrating procedure is repeated to obtain calibration information for a next desired wavelength.

Abstract: In a semiconductor laser device, a flange (33) of a cap (32) is provided with straight-line cut-off portions (34) that are the same in number as notches (36, 37) of a stem (35). With the cut-off portions (34) positioned so as not to overlap the notches (36, 37) of the stem (35) in position, welding between the cap (32) and the stem (35) is performed. The cut-off portions (34) of the cap (32) secure obtainment of a reference plane 38 with a large area in a place where the notches (36, 37) of the stem (35) are absent. As a result, sufficient precision in optical characteristics can be secured while suppressing an influence of unevenness of the stem (35) having a small diameter on a deviation angle ? of an optical axis from a normal line to a reference plane of an optical pickup.

Abstract: To provide a semiconductor device, such as semiconductor laser, having no need of complicated process, ensuring a high yield and mass-productivity necessary for cost reduction, and exhibiting excellent initial characteristics and reliability, nitride semiconductor layers containing a plurality of group III elements are formed on a base body surface having recess (opening) such that the nitride semiconductor layer varies in at least one of composition ratio of the group III elements, band gap energy, refractive index, electrical conductivity and specific resistance within the layer in response to the recess of the base body. In addition, by heating the structure in an atmosphere containing hydrogen and using a layer containing Al as an etching stop layer, controllability and production yield can be improved without influences from fluctuation in etching depth, or the like. Further, etching and re-growth can be conducted consecutively to provide an inexpensive process.

Abstract: An adjustable bipolar current source for a load, such as a thermoelectric cooler, includes a voltage-controlled power supply having a unipolar output, and an H-bridge. At least one of the two active elements on a first side and at least one of the two active elements on a second side of the H-bridge comprises an active conductive element responsive to a control signal to set a magnitude of current flow through the active conductive element. Control logic provides the control signals to the active elements on the first and second sides to set the polarity of the current to the load. Logic coupled to the voltage-controlled power supply maintains a supply voltage sufficient to maintain a voltage drop across the active conductive elements within a linear range of operation of the conductive elements. The output of the voltage-controlled power supply is clamped at or near a minimum stable level.

Abstract: A system and method of minimizing the amount of power that is used by an optoelectronic module is disclosed. The system uses a thermoelectric cooler (TEC) to maintain a case temperature of the module at about 50° C. This allows the TEC to operate in the much more efficient heating mode, thus minimizing the amount of current being used to maintain the module temperature. The method includes the steps of determining a temperature range and operating temperature for an optoelectronic module, such that a maximum current level is not exceeded. In one exemplary embodiment, an operating temperature of about 50° C. with a temperature range of from about ?5° C. to about 75° C. allows a maximum current of about 300 mA.

Abstract: A laser diode array is formed on a substrate (310) in which a number of parallel grooves (312) are formed. A metal layer (410) is formed on the grooves (312). Laser diode bars (314) are fitted in alternate grooves, and every other groove is left vacant to serve as a cooling channel (316). The array is immersion cooled in a housing (210). Liquid coolant is circulated through the housing (210) and through a heat exchanger (216). The liquid coolant flows over a major surface of the substrate (310) and through the cooling channels (316). Thus, heat is removed by circulating fluid from three sides of the laser diode bars (314). Such high-performance cooling permits the laser diode array to have a greater power density.

Abstract: A green diode laser includes a tubular laser casing, a heat sink sealedly mounted at the laser casing, a semiconductor chip supported by the heat sink, an optical resonant cavity supported within the laser casing, including a lasing medium and an intracavity frequency doubler, an IR blocking filter inclinedly and seadedly mounted at the laser casing to optically communicate with an output facet, and a photodiode supported within the laser casing at a position that when the laser beam exits the output facet, the IR blocking filter reflects a portion of the laser beam towards the photodiode such that the photodiode is adapted for detecting the laser beam from the IR blocking filter as a feedback for controlling a power output of the green laser chip.

Abstract: An optical system has a high power diode pump source and a thin disk gain media. An optical coupler is positioned between the diode pump source and the thin disk gain media. The optical coupler produces a beam with a large numerical aperture incident on the thin disk gain media.

Abstract: In a semiconductor laser element having a plurality of semiconductor layers formed on a substrate, a groove-form concave portion is formed on the surface of the substrate opposite to the surface having the semiconductor layers. The concave portion is filled with metal having a higher heat conductivity higher than the substrate. The semiconductor laser element achieves improved heat dissipation characteristics and high reliability even under high-output operation.

Abstract: Disclosed herein is a light source device and a wavelength control device therefor. The light source device includes a plurality of laser diodes, a temperature sensor provided in the vicinity of the plurality of laser diodes, a control loop for controlling the temperatures of the plurality of laser diodes according to an output from the temperature sensor to thereby control the oscillation wavelengths of the plurality of laser diodes, and a unit for compensating temperature control conditions for the laser diodes other than a reference laser diode selected from the plurality of laser diodes, according to a change in temperature control condition for the reference laser diode. By the compensation of the temperature control conditions, the oscillation wavelength of each laser diode can be easily stabilized to each wavelength channel of WDM.

Abstract: A semiconductor laser device has a laser chip, a stem having a block portion on which the laser chip is mounted, and a cap mounted on the stem so as to cover the block portion. The cap has a cutout portion into which the block portion is partially inserted. With this arrangement, the block portion is enlarged, so that the block portion is easily formed integrally with the stem to reduce the manufacturing cost of the stem, and that heat release is increased to improve operating lifetime and the temperature characteristic of the laser element.

Abstract: A housing for opto-electronic array devices. The housing includes a base and walls that form a region that receives an opto-electronic semiconductor array. Conductive traces are disposed on a wall such that a front part of the traces are exposed for external electrical connections, while the back part is exposed for internal electrical connections. A transparent substrate having a plurality of micro-lenses cover the base, walls and opto-electronic semiconductor array device. Each micro lens is beneficially made from optical epoxy that is deposited by an ink-jet nozzle. The base and walls are beneficially comprised of a ceramic.

Abstract: A semiconductor laser device, with which a compact and thin optical pickup can be realized, is provided. On the top surface of a supporting member, there is formed an element mounting area for mounting a series of elements including a semiconductor laser element, and a light detecting element which detects a laser beam emitted from the semiconductor laser element and reflected by a surface of an outside optical disc so as to be re-entered. An optical path from the semiconductor laser element to the surface of the optical disc includes a vertical optical path advancing from the element mounting area of the supporting member in an approximately vertical upward direction. On a pair of right and left opposing ends of the supporting member, arcuate curved outer surfaces are formed, respectively, so as to fit the supporting member into an installation hole, for a semiconductor laser device, having arcuate curved inner surfaces.

Abstract: A plurality of multi-cavity laser diode chips, each having a plurality of light emitting points, are fixed side by side and form a laser diode array.

Abstract: Optical systems of the present invention include optical devices, such as lasers and other optical sources, that are packaged, or housed, in a structure employing a high thermal conductivity, low effective thermal mass member, such as a heat pipe. The high thermal conductivity, low effective thermal mass is positioned in sufficiently close proximity to one or more optical sources that heat generated by the sources is conducted away at a desired efficiency to maintain the package within a prescribed temperature range.

Abstract: A semiconductor laser light source device and light source unit according to the present invention include a first plate-like member made of metal, to which a semiconductor laser array is joined along the end portion, a second plate-like member made of metal, in which an inlet opening portion, which introduces cooling fluid, and a cooling fluid draining channel, and a third plate-like member made of metal, which is formed along the area corresponding to the end portion and to which at least one cooling channel is provided through which cooling fluid flows in the longitudinal direction of the semiconductor laser array by communicating the cooling fluid introducing channel and the cooling fluid draining channel. Thus, the sectional area of the channel can be larger than that in the construction of the related art and the processing cost is reduced by comparison with the construction of the related art.

Abstract: A sub-mount (7) provided with a laser chip (8) and a light receiving element (5) for monitoring is bonded to a die pad portion (2a) of a first lead (2). An electrode of the laser chip and an electrode of the light receiving element are electrically connected to second leads (3, 4) by wires such as metallic wires, not shown, respectively. A resin frame (6) is provided to cover sides and a rear surface side of the sub-mount except for an emission surface side of the laser chip and to integrally hold one end portion sides of the first and second leads. An antireflection unit (9) for preventing light from being reflected on the light receiving element is formed on a portion of the resin frame opposite to the rear end face of the laser chip. As a result, it is possible to obtain a mold type semiconductor laser capable of constantly detect accurate laser chip output and capable of forming an accurate optical output control circuit.

Abstract: For preventing an optical axis from shifting due to a heat cycle in a semiconductor laser module, or in a optical transmitter, the semiconductor laser module comprises, a semiconductor laser element, a frame for storing the semiconductor laser element therein, an optical fiber fixing portion being connected to the frame; and a flange being connected to the frame, and having a fixing portion for fixing the frame on a substrate, wherein the flange has a narrow width region between a fixing region, including a foxing portion with the substrate therein, and the frame, and the narrow width region is narrower than width of the fixing region.

Abstract: In a semiconductor laser module, in order to sufficiently reduce the thermal stress arising in a due to the bonding of elements when they are packaged and to improve the yield of production, the semiconductor laser module is provided with a semiconductor laser element, a submount bonded to the semiconductor laser element with a solder layer in-between and thereby mounted with it, and a base mounted with this submount with another solder layer in-between. Herein, T/W?0.15 holds, where W is the width of the submount in the direction orthogonal to the optical axis of the semiconductor laser element and T is the thickness of the submount.

Abstract: The present invention relates to an optical pickup used for an optical recording information instrument such as CD-ROM, CD-R, MO, DVD and the like, and a semiconductor laser device assembled to be incorporated in the optical pickup, as well as to a method for manufacturing said semiconductor laser device. The present invention also relates to a semiconductor laser element comprising a plurality of semiconductor laser chips, which is incorporated in the semiconductor laser device and to a method for manufacturing said semiconductor laser element, especially to an apparatus for accurately bonding and assembling a semiconductor laser element used in manufacturing said semiconductor laser element, such as a semiconductor laser chip die-bonding machine and the like.

Abstract: There is provided a semiconductor laser device capable of maintaining a good luminous characteristic under severe environment. A cap 4 in an approximate portal shape having lateral apertures 41 is attached to a stem 1 on which a laser diode 2 and a light receiving element 3 are mounted. A holographic element 5 is mounted on a window 43 of the cap 4. Air inside the cap 4 is exchanged with outside air through the lateral apertures 41 to effectively cool the laser diode 2, thus enabling the semiconductor laser device to maintain a good luminous characteristic under high-temperature severe environment.

Abstract: A semiconductor laser device as one example of semiconductor light-emitting devices includes a semiconductor laser chip and a submount serving respectively as a semiconductor light-emitting device chip and a mount member, the semiconductor laser chip including a GaN substrate and a stack. The semiconductor laser chip is bonded to a mount surface of the submount by means of solder, with the stack facing the mount surface. The submount includes a material having a higher thermal expansion coefficient than GaN which is a material for the GaN substrate.

Abstract: The present invention provides a non-laser-active solid which is connected to a laser-active solid which has a reflective layer system and is cooled by a cooling member. Parallel isothermal planes are created in laser-active solid which are passed through by laser beam at a shallow angle. In this manner, a compact laser beam amplifier system is created which functions without a costly beam shaping optical system for semiconductor laser, and has a good beam quality even at high power.

Abstract: An optical transmitter includes a laser driver capable of receiving data and applying the data to drive a laser diode over a transmission line having first and second ends. The first end of the transmission line is coupled to an output of the laser driver. A first terminal of an amplifier is coupled to the second end of the transmission line. A second terminal of the amplifier is coupled to the laser diode. The signal amplitude applied at the first terminal controls optical output amplitude of the laser diode.

Abstract: A laser device which may be used as an oscillator or amplifier comprising a chamber having a volume formed therein and a gain medium within the volume. The gain medium comprises solid-state elements containing active laser ion distributed within the volume. A cooling fluid flows about the solid-state elements and a semiconductor laser diode provides optical pump radiation into the volume of the laser chamber such that laser emission from the device passes through the gain medium and the fluid. The laser device provides the advantages of a solid-state gain medium laser (e.g., diode-pumping, high power density, etc), but enables operation at higher average power and beam quality than would be achievable from a pure solid-state medium.

Abstract: A two-dimensional LD (laser diode) array light-emitting device constituted by stacking light-emitting units each having a LD bar and a cooling assembly for cooling the LD bar with a simplified electrical connection structure to reduce manufacturing cost. The cooling assembly is electrically connected with one electrode of the LD bar through the die spacer so that a part of the cooling assembly serves as one electrode of the light-emitting unit. The other electrode of the LD bar is electrically connected with a webbed extending section of a conductive layer of a TAB (tape-automated bonding) sheet so that the conductive layer serves as the other electrode of the light-emitting unit. A space between the adjacent cooling assemblies for arranging the LD bar is adjusted by the spacer sheet intervened between the TAB sheet and the cooling assembly.

Abstract: A wavelength locked semiconductor laser module has at least one of semiconductor laser of the laser arrays and a heater and/or cooler configured to vary a temperature of the semiconductor laser(s). A phase shifted wavelength locker is configured with wavelength locker temperature sensor and microprocessor to control of the wavelength of the semiconductor laser of the laser arrays instantaneously with absolute precision.

Abstract: In an LED, the area of contact between an ohmic electrode formed on a contact layer and the contact layer serves as an effective light-emitting area of a light-emitting layer. Therefore, while the area of contact between the ohmic electrode and the contact layer is kept small, a seat electrode is interposed so that the seat electrode is connected to a circuit wiring on a wiring board by a ball electrode being contact with the seat electrode at an area larger than the area. As a result, the size necessary for forming the ball electrode can be secured easily and the light-emitting area of the light-emitting layer in the LED can be reduced sufficiently. Accordingly, a capacitance component formed by clamping the light-emitting portion of the light-emitting layer can be reduced, so that a time constant at a leading edge of luminance and a time constant at a trailing edge of luminance can be reduced sufficiently to obtain a high speed.

Abstract: Photonic integrated circuits (PIC) semiconductor chips are provided with thermal isolation and/or heat dissipation structures between integrated optical components in the PIC chip, particularly integrated active optical components. These structures may also serve as a ground path for electrical circuitry on the PIC chip. An important function is the enhanced thermal isolation from, or dissipation of heat from, between adjacent or neighboring optical components in the PIC so that required spacing between adjacent optical components can be made even less than the thickness of the substrate thereby realizing a more compact optical component array on the monolithic PIC chips.

Abstract: In a semiconductor laser device, a plane of polarization of a laser beam emitted by a semiconductor laser (4) is inclined from a substrate surface (4A), allowing the semiconductor laser (4) to be higher in power and higher in reliability. Moreover, a die-bond surface (17) of this semiconductor laser (4) is inclined by a specified inclination angle ? with respect to the reference surface (3) of the stem body (1), so that the plane of polarization of the laser beam can be made generally parallel to the reference surface (3) of the stem body (1). Thus, there can be provided a semiconductor laser device which is capable of contributing to a thinning of an optical pickup device and easy to manufacture.

Abstract: An electronic device such as a laser diode is mounted on a heatsink assembly within a TO-can package. The heatsink assembly is mounted in heat exchange relation with a heat pipe by being on or adjacent a heat pipe. The heat pipe is either attached to an exterior face of the TO-can package or passes into the TO-can package to efficiently draw heat away from the heatsink assembly.

Abstract: Various methods and apparatuses extend the useful operation speed of TO-can optoelectronic packages up to speeds of 10 Gbps and beyond.

Abstract: A cooling device for laser diodes comprising a stem which comprises a 2 mm thick Cu substrate having thereon an array of grooves extending to the resonator length of a laser diode device with a width of 50 ?m and a depth of 300 ?m and a 100 ?m thick Cu cover plate for hermetically sealing the grooved surface by, e.g. soldering. The groove contains a working fluid of deionized water filled under reduced pressure, forming a heat pipe. A plurality of heat pipes is created to form a heat pipe array. Forty GaN laser diode devices each having five light-emitting areas, each of which has an optical power of 100 mW, are mounted with junction-down on the upper surface of cover plate, forming a bar laser with a total output of approximately 20 W.

Abstract: A heat radiator for dissipating heat from an electronic device, which is mounted on a board or which is installed in a casing, to the outside thereof is basically composed of a substrate having plenty of through holes, which are produced by press molding and sintering. The substrate having a low thermal expansion coefficient is made of a copper-tungsten alloy or a copper-molybdenum alloy in which the copper content is smaller than the tungsten content or molybdenum content. The through holes each having a circular shape or a rectangular shape are infiltrated with the compound having a high thermal conductivity and composed of a copper-tungsten alloy or a copper-molybdenum alloy in which the copper content is greater than the tungsten content or molybdenum content. Thus, the heat radiator allows thermal conduction along axial directions of the through holes while substantially avoiding unwanted thermal expansion thereof.

Abstract: A semiconductor laser device has a laser chip and a submount therefor. The submount has a fore end surface inclined in a direction of thickness of the submount. The laser chip is mounted on the submount in such a manner that an edge line of the fore end surface is perpendicular to a light emission axis of the laser chip, and that a light-emitting end surface of the laser chip projects from the edge line by a projection length in the direction of the light emission axis of the laser chip. Thereby, the laser chip receiving no return light is easily positioned with high accuracy.

Abstract: A semiconductor laser element and a protective wall surrounding the element are provided on the surface of a metal frame of a semiconductor laser device. Circumferential portions are provided on an outer periphery of the metal frame for rotating the optical axis of light originating from a light-emitting point of the semiconductor laser element to a direction along the surface of the metal frame. By way of a guide of an optical pickup base corresponding to the circumferential portions, the semiconductor laser device is mounted on the optical pickup base.

Abstract: A resin package 1 is hollowed in order to house components of a hybrid optical module. Laser devices 7 and 8 are die-bonded to metal frames 2 and 3, respectively. Ends of the metal frames are bent, and then embedded into the resin package 1 as in-resin bent portions 4, 5, and 6. In a frame led-out portion 10, portions of the metal frames 2 and 3 are led out to the outside of the resin package 1. The led-out portion 10 is made in contact with a metal plate, an aluminum die cast member, or the like which is outside the package, whereby the heat radiation effect is improved.

Abstract: A semiconductor laser apparatus includes a base, a block, and a semiconductor laser element. The base has a recess on a main plane thereof. The block is perpendicularly elongating on the main plane. The block is neighboring the recess. The semiconductor laser element is mounted on a side of the block. A first end of the semiconductor element is located on outer side of the recess, and a second end of the semiconductor element is located on inner side of the recess.

Abstract: A diode laser arrangement is disclosed wherein a radiation source is designed which can be scaled with respect to power such that different types of cooling can be applied and the configuration of the radiation field is suitable for adapting to different tasks in a simple manner. For this purpose, every diode laser is connected to a thermal contact surface of a separate, heat-spreading carrier which is fastened to a cooling surface of a common cooling element so as to be electrically insulated. The carriers are arranged adjacently in such a way that the line-shaped emission regions of the diode lasers are adjacent in series and the p-n junction planes extend parallel to the thermal contact surfaces. The diode laser arrangement is particularly suitable as a pump light source.

Abstract: A laser bar is soldered to a conventional microchannel copper heat sink whose coefficient of thermal expansion (CTE) is locally modified in the area where the laser bar is soldered to better match the CTE of the laser bar. A strip of ceramic material having a CTE lower than that each of the laser bar and of the copper heat sink is soldered to portions of the metallic heat sink located adjacently to the surface area on which the laser bar is located. The inclusion of the ceramic strips enables a laser bar having a nominal CTE of 6.6×10?6/K, to be soldered directly to a copper heat sink having a nominal CTE of 16.5×10?6/K without incurring thermal distortions at the interface that would limit the useful life of the laser bar.