Abstract: A liquid stabilizing system stabilizes an internal mirror/internal resonator gas discharge laser tube assembly which has a hermetically sealed gas laser tube which includes a gas, a capillary tube, an anode, an anode end assembly, a cathode, a cathode end bell, a cathode end assembly with electrical feed-throughs for the cathode, which are coaxially disposed with a central axis, and laser mirrors, which are sealably mounted to each end of the hermetically sealed gas laser tube. The liquid stabilizing system includes a cylindrical plastic jacket and a cooling liquid. The plastic jacket has a cooling liquid inlet and a cooling liquid outlet and surrounds the hermetically sealed gas laser tube. The cylindrical cooling jacket is sealed to the hermetically sealed laser tube by O-rings which are held in place by plastic retainers. An annulus is formed between the hermetically sealed laser tube and the plastic jacket.

Abstract: In a solid-state laser device comprising a solid-state laser medium disposed in a laser resonator and a semiconductor laser device for exciting the solid-state laser medium, the solid-state laser device comprises a vessel for receiving the solid-state laser medium and the semiconductor laser device. The vessel is filled with a refrigerant so that the refrigerant is contact with at least one part of the semiconductor laser device and at least one of the solid-state laser medium. Connected to the vessel, a temperature controlling device controls temperature of the refrigerant to maintain a predetermined desired temperature so that the excitation laser beam has an excitation wavelength which coincides with an absorption wavelength of the solid-state laser medium. The refrigerant may composed of an insulated transparent liquid or an inert gas.

Abstract: A diode laser array made from a plurality of linear laser diode array assemblies affixed and in good thermal communication with bodies containing micro-heatpipes. Assemblies are stacked in a vertical manner to form two dimensional arrays. Each assembly is connected electrically and mechanically to adjacent assemblies to form the final assembly. In one embodiment the bodies are arranged in a vertical stairstep manner such that radiation from an upper assembly stimulates emission in adjacent lower assemblies thereby achieving frequency locking. In another embodiment said micro-heatpipe containing second bodies are fabricated from materials with a coefficient of thermal expansion closely matching with a coefficient of thermal expansion closely matching that of the laser diode array subassemblies. In another embodiment the assemblies form the evaporator of a second heatpipe device cooling means.

Abstract: A compact flowing gas laser, particularly a CO.sub.2 gas laser, wherein the path or paths between the outlet or outlets and the inlet or inlets of one or more optical resonators contain a turbine whose impeller or impellers are driven by heated gas and which drives the impeller or impellers of a rotor forming part of a compressor serving to compress the thus cooled and expanded gaseous lasing medium prior to reentry into the resonator or resonators. A first heat exchanger is installed between the turbine and the compressor, and a second heat exchanger is provided downstream of the compressor.

Abstract: A solid state laser apparatus comprises a laser medium having a pair of optically flat surfaces confronting to each other, and side surfaces intersecting the optically flat surfaces along an optical axis, the laser medium having a rectangular cross section; heat insulators adhered to the side surfaces of the laser medium; and reflective films for shielding the thermal insulators from pumping light. A solid state laser apparatus may comprise heat conductors bonded to the side surfaces of the laser medium, the heat conductors removing heat which occurs at bonding surfaces, the amount of removed heat from the side surfaces being smaller than that from the optically flat surfaces.

Abstract: An improved housing for use in a laser pump module, including a laser rod housed within a sleeve and laser diodes providing the rod excitation, wherein the main housing structure is constructed from a single piece of material and formed with internal interconnected internal passageways to provide for efficient cooling of the pump sources and the sleeve provides the outer wall of the coolant passage for cooling of the laser rod.

Abstract: An improved housing for use in a laser pump module, including a laser rod housed within a sleeve and laser diodes providing the rod excitation, wherein the main housing structure is constructed from a single piece of material and formed with internal interconnected internal passageways to provide for efficient cooling of the pump sources and the sleeve provides the outer wall of the coolant passage for cooling of the laser rod.

Abstract: A metal vapor apparatus comprising a laser tube within which laser action occurs during operation of the apparatus, and means for applying a liquid metal coolant to the tube.

Abstract: A laser structure that reduces thermally-induced mounting stress on low fracture strength solid-state laser rods. A transparent sleeve of relatively high strength optical material that has relatively high thermal conductivity is provided around the laser rod, and a thin layer of elastomer is provided between the laser material and the transparent sleeve. This arrangement of laser material, transparent sleeve, and elastomer allows sealing of a cooling fluid flow channel disposed around the laser/sleeve assembly using conventional means without applying stress directly to the laser rod material. This reduces the risk of fracturing the laser rod material due to thermal expansion near the seal and allows the laser to be operated at higher average power levels. The elastomer layer and high thermal conductivity sleeve efficiently conduct heat from the laser rod to the surrounding cooling liquid.

Abstract: Integrated microsystem comprising electrical and nonelectrical, particularly optical functions in a laser system, wherein a base comprising anisotropically etchable semiconducting material on which etching structures for receiving optical and/or electro-optical and electrical/electronic and/or fluidic and/or mechanical elements or their mountings are arranged in predetermined distances and/or levels, as well as integrated switching circuits, and that at least a part of the optical, electro-optical or mechanical elements or their mounting is controllable and movable electrically in such a way that its position relative to the base is actively changeable, and that at least one sensor is provided which determines the effect of the position change on the function of at least a part of a microsystem and supplies a signal for repeated readjustment (self-adjusting) of optical elements and their mounting.

Abstract: A semiconductor mounting package is provided which permits the active p-n junction of a light emitting semiconductor to be operated in a liquid heat transfer fluid. The package provides optical coupling for extracting light energy.

Abstract: In a solid state laser assembly (12), arrays (60) of pumping laser diode bars (62), placed on opposed sides of a laser rod (36), are maintained at an optimal operating temperature by a pair of heat pipes (16) physically and thermally coupled at their respective evaporator sections (18) to both the diode bars and the laser rod. The laser assembly includes a pump cavity (34) configured as an I-beam having two pairs of terminal interfaces (58) respectively bounding a pair of elongated U-shaped channels (48). Heat from laser rod (36) is conducted through pump cavity (34) to the heat pipe evaporator sections (18). A mounting block (64) physically and thermally supports each of the diode array assemblies for spreading heat therefrom also to the evaporator sections.

Abstract: A gas laser is designed with the following features: The laser is a slab laser, in which a plasma space (5) of a limited height is formed for the laser-active plasma between mutually opposing surfaces (11, 21) of two wall parts (10, 20); the wall parts (10, 20) are components of a coupling chamber with at least one coupling wall (30), which is connected to at least one distribution chamber (40,), whereby by injecting the high-frequency energy through the coupling wall (30), the gas plasma is activated in the desired manner over its entire length. The high-frequency energy for exciting the plasma lies in the gigahertz range, for which a magnetron is used, for example.

Abstract: Atoms in a neodymium:glass rod 20 are excited to a substantially spatially uniform metastable state by flashlamps 21. A flowing fluid 26 cools the flashlamps, but not the rod; so that low temperature gradients are maintained in the rod during isothermal laser operation. Automatic control means 22 turn off the electrical power supply 24 when the temperature in the rod reaches a predetermined limit. A flowing fluid 23 then cools the rod, at a rate low enough to avoid thermal stress therein, while it is not lasing. Segments of reflectors 25 focus the pump photons in the rod so as to substantially balance the cylindrical lensing action of the rod against the radial attenuation through it, and thus to provide substantially uniform density of stored energy in the rod.

Abstract: Coupling apparatus for a large bore metal vapor laser is disclosed. The coupling apparatus provides for coupling high voltage pulses (approximately 40 KV) to a metal vapor laser with a high repetition rate (approximately 5 KHz). The coupling apparatus utilizes existing thyratron circuits and provides suitable power input to a large bore metal vapor laser while maintaining satisfactory operating lifetimes for the existing thyratron circuits.

Abstract: A laser apparatus is disclosed which is capable of protecting the laser slab or rod crystal within the laser from damage due to overheating when the laser malfunctions in a manner such that laser output ceases while optical pumping of the laser crystal continues. The laser apparatus includes a laser crystal situated within a laser cavity. The apparatus also includes an excitation lamp for pumping the crystal to generate a laser beam to project along a desired main path. A first sensor senses the cessation of the projection of the laser beam along the desired main path and a second sensor senses the continuing excitation of the excitation lamp. The apparatus further includes a extinguishing circuit for extinguishing the excitation lamp a predetermined amount of time after the cessation of the laser beam such that damage to the laser apparatus due to overheating is avoided.

Abstract: A gas laser includes an inner tube filled with gas and having mirrors at its opposite ends to define a resonant chamber, an outer tube filled with gas and defining a gas reservoir for the gas in the resonant chamber, and electrodes for energizing the gas in the resonant chamber. The gas reservoir includes a pair of intermediate tubes coaxial with and between the inner and outer tubes. One of the intermediate tubes is open at one end facing one end of the laser and is joined at its opposite end facing the opposite end of the laser to the outer tube. The other intermediate tube is open at its end facing the opposite end of the laser and is joined at its end facing the one end of the laser to the inner tube, whereby the pair of intermediate tubes divide the reservoir into a plurality of annular spaces defining a zigzag path between the opposite ends of inner tube.

Abstract: The present invention provides a heat-resistant electrical insulator adapted for joining laser housing portions, which insulator comprises: an annulus; a channel in the annulus traversing the circumference and length of the housing; at least two ports, each communicating with the channel and an outer surface of the housing; and an attachment for securely attaching each end of the annulus to a laser housing member.

Abstract: A device for analyzing the distribution of energy within a power laser beam includes a thermoelectric receiver (1) directly exposed to the laser beam (2) and delivering electrical signals to an intermediate demultiplexer and amplifier device. The device operates in continuous mode and in impulse mode, the thermoelectric receiver being constituted by a sealed body (5) whose surface turned toward the source of the laser beam is metallic and constitutes, in cooperation with metallic wires (7), the support of the thermocouples. The wires (7) pass in sealed manner through the surface (8) of the body (5) opposite the surface turned toward the source of the laser beam (2), and the body (5) is provided moreover with two openings (9) for circulation of a cooling fluid.

Abstract: It is an object of the present invention to provide A laser device of long life. In the laser device, light source is housed in transparent cooling vessel, and the vessel is filled with a cooling liquid which is circulated. The electrodes of the light source project out of the cooling vessel. Reflectors are provided outside the cooling vessel. The electrodes and the reflectors are out of contact with the cooling liquid.It is another object of the present invention to stabilize laser oscillation. A light source is housed in a first transparent cooling vessel. The first cooling vessel is filled with a first cooling liquid. A laser medium is housed in a second transparent cooling vessel. The second cooling vessel is filled with a second cooling liquid. A heat insulation layer is provided between the first and the second cooling vessels so that the first and the second cooling liquids are thermally insulated from each other.

Abstract: A lighting device comprises a light source, a light reflective cylinder, and a light receiving surface receiving light directly from the light source and another light reflected from the light reflective cylinder. The light reflective cylinder has a shape such that light intensity on the light receiving surface is constant. The light source is a linear source of light. The light receiving surface has a width W and includes a flat surface extending in parallel to the optical axis of the linear source of light. The light reflective cylinder extends continuously from opposite ends of the flat surface and is composed of plates each extending in parallel to the optical axis of the linear source of light and having a very small width.

Abstract: A metal vapor laser has a discharge tube with electrodes at opposite ends. A power source is electronically connected to the electrodes and generates a discharge in a discharge region within the discharge tube. The discharge generates laser light which emerges from the tube via windows. In order to cool the apparatus, the discharge tube is surrounded by a cooling jacket in the form of a hollow cooling vessel. A liquid flows in the cooling vessel and removes heat. The space between the cooling vessel and the discharge tube is evacuated. The cooling vessel is conductive and, since it is connected between one of the electrodes and the power supply, its inner and outer walls provide two potential paths for return current. The fact that the inner and outer walls have different diameters means that the inductance of the return paths is large. Therefore, the outer wall has a gap in it filled with insulating material.

Abstract: A solid state holmium laser is described which comprises an elliptical or double-elliptical cavity in which pumping lamp(s) are located along one focal line of the ellipse(s) of a one piece cavity and a holmium laser rod is located along the other fold line of the ellipse(s). The laser rods are held by a rod holder and coupled to a source of coolant and a cooling mantle is provided on a cylindrical body forming the cavity.

Abstract: A laser diode array is disclosed that includes a plurality of planar packages and active cooling. The laser diode array may be operated in a long duty cycle, or in continuous operation. A laser diode bar and a microchannel heat sink are thermally coupled in a compact, thin planar package having the laser diode bar located proximate to one edge. In an array, a number of such thin planar packages are secured together in a stacked configuration, in close proximity so that the laser diodes are spaced closely. The cooling means includes a microchannel heat sink that is attached proximate to the laser bar so that it absorbs heat generated by laser operation. To provide the coolant to the microchannels, each thin planar package comprises a thin inlet manifold and a thin outlet manifold connected to an inlet corridor and an outlet corridor.

Abstract: A laser diode array is disclosed that includes a plurality of planar assemblies and active cooling of each assembly. The laser diode array may be operated in a long duty cycle, or in continuous operation. A laser diode bar and a microchannel heat sink are thermally coupled in a compact, thin planar assembly having the laser diode bar located proximate to one edge. In an array, a number of such thin planar assemblies are secured together in a stacked configuration, in close proximity so that the laser diodes are spaced closely. The cooling means includes a microchannel heat sink proximate to the laser diode bar to absorb heat generated by laser operation. To provide the coolant to the microchannels, each thin planar assembly comprises passageways that connect the microchannels to inlet and outlet corridors. Each inlet passageway may comprise a narrow slot that directs coolant into the microchannels and increases the velocity of flow therethrough.

Abstract: A laser package includes a laser with first and second spaced terminals and a layer between the terminals with properties of emitting light when voltage pulses are applied between the terminals. A current of a particular magnitude is produced between the terminals in the time periods between the voltage pulses. The voltage required to produce such current is dependent upon the layer temperature. Variations in this voltage produce variations in the rate of pulses from a thermoelectric cooler included in the laser package. Variations in the rate of such pulses from the thermoelectric cooler affect the rate at which heat is withdrawn by the thermoelectric cooler from the laser. A cooler body is disposed adjacent to the thermoelectric member and is constructed to pass a cooling fluid through the cooler body to cool the thermoelectric member. The cooling fluid passes through an inlet port to a plurality of channels converging at a central recess.

Abstract: A plurality of lasers, each regulated to operate at a particular temperature, are supported by a manifold to direct coherent light into space. The regulation may be provided by producing pulses of a trickle current of a particular magnitude through the laser, measuring the voltage required to produce the trickle current and adjusting the characteristics of a thermoelectric member in accordance with the magnitude of such voltage to adjust the rate at which the thermoelectric member transfers heat from the laser. The lasers produce substantially parallel and thin beams of light in pairs. The light beams in each pair provide an optimum angle for the interception by such paired beams of particles having individual trajectories in space. These particles scatter the light to a receiving lens system disposed within the manifold. The received light then passes through masks which restrict the collected light to a spatial pattern corresponding to the pattern of the light beams from the lasers.

Abstract: Pumping laser diodes (3) are disposed around a reflector tube (2) having narrow windows (14) through which the emitting areas of the diodes look. The tube leaves an angular gap (16) around a rod to be pumped (1) and a cooling liquid flows in said gap. The invention is particularly applicable to optically pumping a YAG rod.

Abstract: A high power phase coupled waveguide laser comprising a plurality of symmetrically disposed lasing members disposed around the outer periphery of an annular enclosure. The laser includes an annular body of dielectric material having a multiplicity of laser cavities formed therein in a symmetrical annular array. The body includes a central bore having conduits extending therethrough for providing a flow of cooling fluid. The heat path between the cavities and the cooling fluid is symmetrical for all cavities. This provides equal conditions for all laser cavities in the array and ensures phase coupling of all cavities.

Abstract: An improved pumping arrangement for use in a face pumped or edge pumped slab laser, this arrangement comprising upper and lower housing members able to be removably secured together in an operational relationship. The lower housing member has in a central portion thereof, a body of solid state laser host material, with the laser host material typically having a rectangular cross-section with top and bottom surfaces, opposing side surfaces, and opposing end faces. The lower housing member also is configured to have a pair of spaces running the length of the laser host material. The upper housing member has on its underside, a pair of parallel flashlamps set a distance apart. The lower housing member is able to receive the upper housing member in an interfitted, operative relationship, in which the flashlamps are received in the respective spaces alongside the body of solid state laser host material.

Abstract: An apparatus for purifying laser gas comprises first and second tubes 20, 22 in good thermal contact, liquid nitrogen flowing through the first tube 20 and laser gas flowing through the second tube 22. The laser gas is precooled in an arrangement of third and fourth tubes 24, 26, the laser gas to be cleaned entering the third tube 24 which opens into the second tube 22 so that precooled laser gas enters the second tube which opens into the fourth tube to effect the precooling.

Abstract: An optically pumped laser comprising a securing arrangement (14) for the bar assuring, on one hand, the rigid interconnection of the bar (4) and the framework (12a, 12b, 12c, 12d) by gripping the former and in bearing on the latter and, on the other hand the thermal insulation of the lateral faces of the bar. The securing arrangement (14) is obtained from an elastically deformable fitting of plastics material.

Abstract: An Nd/YAG slab laser (1) is pumped by laser diodes (2) placed at a distance from the laser slab. Reflectors (7) convey the light from the diodes to the slab. The distance is such that the density of such light is made uniform. A cooling fluid flows along a compartment (5) between the diodes and the slab. The invention is applicable to producing infrared coherent light.

Abstract: The invention discloses an optically pumped laser comprising suspension means (7) for the bar (2) having inherent elasticity for assuring elastic gripping of the latter. The suspension means (7) comprise at least two suspension elements (17a, 17b) having a generally planar form extending parallel to the pumping faces of the bar. Each suspension element exhibits at least one peripheral securing zone (19a, 19b), a central clamping zone (20a, 20b) and an elastically deformable intermediate zone (21a, 21b) coupling these latter.

Abstract: Laser apparatus comprising an integrating cavity, at least one lens and a heat sink arrangement that provides for a more uniform stored energy distribution, higher energy transfer efficiency and relaxed temperature control requirements. The laser apparatus incorporates a laser rod enclosed within a cavity. The cavity includes optically transparent heat sink means contiguous with and surrounding the laser rod. At least one laser diode array is disposed in a spaced relationship with respect to the axis of the rod. At least one lens is disposed between the diode array and the rod. The lens has a focal length and is disposed to focus light from the laser diode array onto the rod. The cavity is surrounded by reflective surfaces and is provided with at least one elongated aperture therethrough for passing light from the diode array into the interior of the reflecting cavity and onto the rod. The reflective surfaces reflect unabsorbed light passed through the rod for multiple passes through the laser rod.

Abstract: A gas laser with a discharge bore defined by a single-bore extruded ceramic discharge tube is disclosed. An outer tube is located over the discharge tube so as to define an annular space therebetween. Caps are located over both ends of the tubes and each cap is provide with at least one gas transport passage so the discharge bore and the annular space are in communication. The annular space is filled with electrically insulating, thermally conducting components such as washers, baffles and ceramic granules. When the laser is in operation the annular space serves as a gas return path so a uniform equilibrium pressure is maintained in the discharge bore. The components in the annular space inhibit the flow of electrical current in the space so all of the current flow is through the discharge bore so as to excite the gas therein. The components in the annular space also provide a thermally conductive path between the discharge tube and the outer tube to diffuse heat away from the discharge bore.

Abstract: A control apparatus for a pumped rod-type laser includes an arc lamp disposed to illuminate the lasing medium, such as a NdYAG crystalline rod. The apparatus includes a full wave rectifier to power the arc lamp, and a MOSFET switching circuit to turn on and off the arc lamp power at controlled times during each half cycle of the power waveform so that the laser medium is pumped and optically discharged once during each half cycle of the power supply. The laser power output is measured by a photodetector during each half cycle, and the photodetector output is integrated and compared with a manually set, variable laser output power level. When the actual laser power reaches the preset power level, the comparator initiates turning off the MOSFET switching circuit power for that respective half cycle of the power waveform. The full wave rectified power supply also permits the use of 110 VAC utility power.

Abstract: In order to improve an electrically excited, diffusion-cooled highpower laser comprising two wall surfaces slightly spaced from one another and forming an optical waveguide, the width of the wall surfaces being a multiple of the space between them and the surfaces enclosing between them a flow-free discharge chamber, and also comprising an optical resonator having resonator mirrors disposed at both ends of said waveguide, such that his results in a laser beam which can be well focused, it is suggested that the resonator be an optically unstable resonator including a beam path extending lengthwise of a resonator axis and having an expansion transverse to the resonator axis extending as far as at least one exiting laser beam and that the transverse expansion extend transversely to a longitudinal direction of the waveguide and approximately parallel to the wall surfaces.

Abstract: There is provided a gas discharge laser with a purality of elongated parallel electrodes defining in space a honeycomb structure in the form of a plurality of immaginary triangular or square structures, where in the case of the triangular arrangement each of the three parallel electrodes of a given triangle is supplied with DC power with three potentials phase shifted by 1, 120 and 240 degrees; in the case of square electrode arrangements, each of the four electrodes of a given square being supplied with four potentials, phase shifted by 0, 90, 180 and 270 degrees, to the four corners of such adjacent electrodes. At one end of the electrode pattern there is provided a feedback mirror, at the other end an output coupler.

Abstract: A multiple crystal, single pumping cavity laser system comprises an optical pumping cavity, several laser crystal rods disposed in the cavity and having differently sized diameters and with their axes parallel, an optical coupling device for coupling the rods in a chain of increasing diametrical size, an optical pumping source for providing an optimum pumping level for the largest rod, and attenuators for all but the largest sized rod for attenuating the energy absorbed by the smaller rods. Since all of the laser rods are disposed and pumped in a single pumping capacity, only a single pumping source is required. The housing containing the pumping cavity is thermally and mechanically isolated from the rail holding the other system components to prevent shock from being transmitted to the other components.

Abstract: In a laser device having a laser medium and a laser pumping device associated therewith the improvement including an apparatus for efficiently dissipating heat generated in the laser medium to maintain the laser medium at a more suitable operating temperature, the apparatus including an elongated closed ended heat pipe having a first portion in closely spaced proximity and in heat conductive relationship to the laser medium and a second remote end portion in heat conductive relationship to a heat sink, the heat pipe having an outer conductive layer with a coating of a fluid absorbing material positioned therein and forming a passage therethrough, and a heat transfer fluid positioned in the heat pipe and absorbed by the absorbent material, the absorbed fluid adjacent to the laser medium heating when exposed to the heat generated in the laser medium whereby the fluid moves through the heat pipe to a remote location for conduction of the heat therein into the heat sink.

Abstract: An optimized design for a resonator for a laser housing and assembly is disclosed, comprising a concentrically arranged plasma tube, magnet and resonator tube with the mirrors and associated optics housed at opposing ends of the resonator tube, mounted on rods extending from respective ends of the resonator tube.

Abstract: In a laser apparatus which includes a laser medium exhibiting thermally induced optical distortions, and flash lamp mounted near the laser medium to provide laser pumping radiation, an absorbing filter is mounted between the flash lamp and the laser medium for absorbing radiation in the output spectrum of the lamp which exhibits a low fluorescence efficiency in the laser medium. By absorbing radiation with the low fluorescence efficiency in the laser medium, heat which develops in the laser medium can be limited to control the thermally induced optical distortions.

Abstract: A gas laser generator comprises a frame, a gas channel through which a gas flows, a mirror for obtaining a laser beam, defining a resonant cavity, an anode electrode and at least two first and at least two second cathode electrodes arranged in the lower and the upper portions of the resonant cavity, respectively, and a power source, in which a first voltage of a first electric field between the first cathode electrodes connected to the power source through a first ballast resistance and the anode electrode and a second voltage of a second electric field between the second cathode electrodes connected to the power source through a second ballast resistance and the anode electrode are so determined that the former is smaller than the latter so that the current flowing in the first electric field may be substantially equal to the current flowing in the second electric field during the electric discharges between the electrodes.

Abstract: A moving solid state laser gain structure is optically pumped by optical pumping radiation derived from a remote bank of diodes, preferably laser diodes. The pumping radiation is guided and concentrated from the bank to the laser gain structure over a bundle of fiber optic waveguides. In some embodiments, the laser gain structure is a slab of Nd:Glass or Nd:YAG. In some embodiments, the lasant beam is internally reflected within the slab over a zig-zag path. In one embodiment, the lasant slab is a rotating and translating disk with the pumping radiation being applied collinearly of the beam of lasant radiation. In another embodiment, the lasant slab is made up of a bundle of fiber optic waveguides.

Abstract: A solid-state laser system for producing a frequency-doubled CW laser output beam having a stabilized output. The laser system includes within a three-mirror resonator cavity, a Nd: YAG laser rod operating at an output wavelength of 1.064 .mu.m in the TEMoo transverse mode, and a KTP frequency-doubling crystal. At one end of the laser cavity the beam is reflected from a folding mirror through the frequency-doubling crystal to another reflecting mirror which reflects both the fundamental wavelength of the output beam from the laser rod, and also the doubled frequency beam at a wavelength of 0.532 .mu.m back through the frequency-doubling crystal onto the folding reflector. The folding reflector is coated to reflect light at the longer wavelength but transmits substantially all of the light incident upon it at the 0.532 .mu.m wavelength.

Abstract: A laser has a slab in which the beam F is propagated in zig-zag manner between two opposing faces which have the property of ensuring total reflection. For this purpose each of these faces is covered with a solid layer of a good heat conducting material and having a refractive index below that of the slab. Its thickness is preferably greater than three times the operating wavelength of the laser. Thus, a cooling fluid can be in contact with the solid layer to effectively cool the slab. Pumped energy sources are preferably provided opposite the layers.

Abstract: This invention relates to an external cavity slab laser system for pulsed or continuous wave operation consisting of an optically excited, water cooled single or multiple active mirror slab configurations with the external cavity formed by the active mirror and a passive mirror set parallel to each other and separated from each other by a distance greater than the thickness of the slab. Laser beams of both circular and elliptical cross-section can be amplified by the invention which has application in medical apparatus, industrial workstations and defense systems.

Abstract: A glass ceramic reflector having a uniform material composition which has an almost 100% reflectivity that is diffusive in the reflectance range of the entire solar spectrum from 450 to 900 nm wavelength. Furthermore, the ceramic material has a high absorption of ultraviolet wave lengths and low reflectivity in the infrared region to minimize thermal loading of the laser rod of high gain laser material. In one preferred embodiment, the glass ceramic reflector is mica based and has a composition of approximately 55% crystal and 45% residual glass, thereby defining a microstructure that enables the ceramic material to be machined to form an interior surface configuration that is easily closely coupled to flashlamp and laser rod components of the laser device.

Abstract: Optical and thermal distortion in a solid state slab geometry laser are controlled by active siderails disposed at the lateral surfaces of the slab. Each siderail may have a fluid passage therethrough and be connected in a separate fluid circuit which enables the volumetric flow rate and temperature of the fluid through the passageway to be controlled in order to control the temperature of the siderail and, accordingly, the temperature of the slab in regions proximate to the siderail. The invention enables compensation of asymmetric transverse gradients to afford a uniform transverse temperature distribution.