Abstract: A laser cavity optical system is provided for stabilizing the laser far field dominate lobe so that no beam shift occurs. The laser cavity optical system comprises a lens system positioned at one facet of a phased array semiconductor laser for imaging the near field pattern of the laser comprising a single beam waist position in a first spatial direction and reimaging the far field pattern in a second spatial direction after having first focused the far field pattern in the second spatial direction to a single beam waist position. The improvement in the laser cavity optical system comprises a partially reflecting, partially transmitting mirror located at the second spatial direction beam waist position to stabilize the laser beam and prevent laser beam shift at higher operating powers and operating temperatures. Feedback means provided in the system is capable of either spatially or angularly discriminating relative to far field lobes present in a portion of said reflected light output.

Abstract: A laser beam projection device includes a laser plasma tube assembly having a laser plasma tube and a generally cylindrical casing surrounding the tube. The plasma tube is positioned within the casing such that the beam produced by the tube is aligned with the casing and emerges from the casing through a circular opening at one end thereof. A support frame is provided for mounting the laser plasma tube assembly and also for mounting one or more optical elements in precise alignment with respect to the beam produced by the tube assembly. The frame includes an annular member for engaging the circular opening in the casing in order to align the casing with respect to the frame. The frame further defines a pair of non-parallel alignment surfaces, spaced from the annular member, to contact the outer surface of the casing near the end thereof opposite the circular opening. The casing defines an inner beveled surface surrounding the opening through which the beam emerges.

Abstract: A pulsed electrical discharge gas laser uses acoustic diodes to cause the gas to circulate between the active region of the laser and a gas heat exchanger. The diodes take the form of asymmetrical obstacles placed within the gas flow exhibit asymmetrical resistance to the passage of compression waves in the gas that are generated by the electrical discharge and, as a consequence, cause a net flow of gas in one direction through the obstacles, thus causing the gas to circulate from the active region of the laser through the gas heat exchanger and return. A series of columns having cup-shaped cross sections act as the acoustic diodes.

Abstract: The present invention relates to a specific holding structure of a slab geometry crystal for a total internal reflection, slab geometry laser (otherwise known as face pumped laser) device. Both sides of the crystal are held by side rails, and on both longitudinal end portions of the crystal o-ring backing flanges and box-shaped end pieces, respectively, are put on. Furthermore, an o-ring is put in between the end piece and the o-ring backing flange on each end portion of the crystal, and it is compressed to seal the crystal. This o-ring can be made of translucent elastomer. Accordingly, the slab geometry laser device that is compact and easy to remove from, or place into the pump station is provided.

Abstract: A laser apparatus having an optical resonator composed of two end adjustably mounted mirrors positioned at each end of a YAG laser rod. In order to obtain mechanical stability and protection from the environment, concave mirrors having a radius of curvature of less than one meter are each installed in the mount. The mount includes a mirror cell which is preloaded into the mount housing using a generally truncated cone or belville washer shape as a spring. The center of the mirror is gimbaled about a bearing in the mirror cell. Once of the mirror is aligned, it is cemented in position. Thus, the mount combines a short radius of curvature mirror to reduce the sensitivity to optical and mechanical perturbations with a mount to provide mechanical stability in a high-shock environment.

Abstract: A neodymium YAG laser is pumped by a matched laser diode of high efficiency, resulting in a compact, high-efficiency and long-lifetime laser assembly. Output is in the near infrared range, but can be converted to the visible spectrum by an internal frequency doubler. A doubling crystal, which may be a KTP crystal, is placed at an optimum location in the laser cavity. Polarization of the beam may be achieved simply by stressing the YAG rod, prior to frequency doubling.

Abstract: A transverse gas flow RF pumped waveguide laser has been developed utilizing RF discharge waveguide technology in several infrared lasers. Two potential applications have been identified; the pulsed chemical laser and the CW CO.sub.2 laser. In the chemical laser, the flowing gas device provides rapid gas replenishment to maintain high electrical efficiency at high repetition rates. In the CW CO.sub.2 laser, the flowing gas provides efficient cooling so that high output power per unit gain length can be achieved.

Abstract: A plasma tube for a gas laser includes a series of heat webs and insulative spacers between the heat webs, with tungsten bore insert members supported by the heat webs and having aligned apertures defining a laser discharge path. To produce the plasma tube, the heat webs, spacers and other connected components are assembled in a vertical stack outside the ceramic tube of the laser, with a stacking gauge which helps assure that the heat webs are correctly spaced apart within close tolerances. The heat webs lie adjacent to annular metallized areas on the inside surface of the ceramic tube when the assembly is inserted into the tube, which is precision-formed ceramic tubing. The tube assembly is heated in vertical orientation to expand the heat webs diametrically so that they engage outwardly against and are brazed to the metallized areas of the ceramic tube.

Abstract: The invention is a switch to permit a laser beam to escape a laser cavity through the use of an externally applied electric field across a harmonic conversion crystal. Amplification takes place in the laser cavity, and then the laser beam is switched out by the laser light being harmonically converted with dichroic or polarization sensitive elements present to alter the optical path of the harmonically converted laser light. Modulation of the laser beam can also be accomplished by varying the external electric field.

Abstract: Laser energy is combined using dynamic beam splitters that can automatically accommodate changes in the laser cavity mode structure. Nonlinear optical methods and real time holography are employed to achieve phase locking among multiple lasers. A single laser output beam can be produced from a multitude of laser cavities which collectively contribute to the output power. No outside monitoring and servo mechanisms are required, since nonlinear optical processes automatically perform the functions of both monitoring and control. A coupled laser system includes two or more lasers, each laser having a resonant cavity, a laser gain medium in the resonant cavity, and a nonlinear optical element. Each nonlinear optical element is positioned in its respective resonant cavity to diffract laser energy from the cavity to a coupling beam by means of four-wave mixing (phase conjugation).

Abstract: A laser medium containing a chromium (3+) doped germanate garnet represented by the general formula: Ca.sub.3 M.sub.2(1-x) Cr.sub.2x (GeO.sub.4).sub.3 wherein M is Al.sup.3+, Ga.sup.3+, Sc.sup.3+, Lu.sup.3+, or Y.sup.3+ and 0<x.ltoreq.0.25 is disclosed. A laser employing the above-described laser medium is also described.

Abstract: The output of a continuous wave modelocked Nd:YAG laser is first pulse compressed and then frequency doubled from infrared to green, to provide a new pumping source for a synchronously pumped dye laser. The disclosed apparatus and methods can achieve tunable subpicosecond pulses at relatively high average power, over 300 milliwatts. The 1064 nanometer output of the pulse compressor is frequency doubled to 532 nanometers so as to provide 3.5 picosecond pump pulses at 82 MHz and average power exceeding one watt. When this is used to pump a Rhodamine 6G dye laser, tunable pulses as short as 190 femtoseconds output can be obtained from the dye laser, with average power over 300 milliwatts. With the addition of a cavity dumper, tunable subpicosecond pulses of 80 kilowatt peak power have been generated.

Abstract: A high-power laser, especially one with a gaseous excitation medium, having an unstable optical resonator is disclosed. Fully reflecting mirrors, whose planes of curvature are parallel to one another, form the ends of the unstable optical resonator. A third mirror is concavely curved in a plane perpendicular with respect to the other two mirrors. The mirrors have a rectangular cross section and are preferably metallic. The mirrors constituting the ends of the unstable optical resonator form a confocal resonator.

Abstract: A laser generator has a discharge unit which is freely mountable on and dismountable from the laser generator as an integral unit. The discharge unit includes a pair of laser tubes, a pair of flow control units, and a manifold block. Clamp blocks support the laser tubes against movement in the lateral and vertical directions and tapered liners allow adjustment of the height of the laser tubes. Hangers are included in the discharge unit so that the laser tubes may be suspended during mounting and dismounting.

Abstract: A xenon fluoride (C.fwdarw.A) laser operating in the visible region is improved by the use of a synthesized buffer gas containing at least two components that combine to provide kinetic properties that are different from those of any single-component buffer gas.

Abstract: A miniaturized inert gas ion laser is proposed whose discharge column has a diameter between 6.times.10.sup.-3 cm and 8.times.10.sup.-2 cm. In a preferred embodiment, a BeO plate is enclosed by two metal parts which lie against one of the base areas of the plate. One metal part is a copper sheet functioning as anode and the other metal part forms a cavity in which the cathode is situated. The BeO plate is provided with a longitudinal bore which is terminated at both sides by mirrors and communicates via plate perforations with the anode and the cathode space. The bore is 0.1 mm in size and 30 mm long; the discharge occurs on a path of 10 mm; discharge current, discharge voltage and filling pressure lie at 200 mA, 130 V and 5 Torr; the output power amounts to about 1 mW. This type of laser is extremely compact; it is particularly suitable as a stable frequency signal generator and can be simply amplitude-modulated and/or frequency-modulated.

Abstract: A flow control device in a laser generator has a flow control valve disposed opposite a ring member to form an orifice. Laser gas flows from an inlet port into the flow control device, through the orifice, through the flow control valve and into the laser tube. The flow control valve is moveable axially toward and away from the ring member to vary the orifice to control the flow of laser gas in the laser tube. The laser tube also has a sub-hole for a sub-flow of laser gas in the laser tube. A throttling valve is disposed in the flow control device to throttle the flow of laser gas in the sub-hole.

Abstract: In a solid-state laser device comprising a laser oscillation medium and a laser amplification medium, a reflector member has an internal wall surface defining a single prismal space in which both of the oscillation and the amplification media are placed. A flash lamp is intermediate between the oscillation and the amplification media in the prismal space to activate both media in common. The oscillation and the amplification media are of a rod type and a slab-type, respectively. Preferably, the prismal space is divisible into an elliptic cylinder space having in cross section two ellipse focal points and a parabolic cylinder space having in cross section a parabola focal point common to one of the ellipse focal points. The oscillation medium is placed on another one of the ellipse focal points while the flash lamp is placed on the parabolic cylinder space and interposed between the oscillation and the amplification media.

Abstract: A capillary bore laser tube is constructed to have little or no power loss when subjected to relatively high shock loads during operation. A spider structure supports the free end of the capillary bore tube in an almost rigid manner against transverse movement of the free end with respect to the outer envelope or jacket of the laser tube so that high shock loads and vibration produce little or no permanent change in the radial alignment of the free end of the bore tube with respect to the other operating components of the laser tube. The spider structure is a disk shaped member which is rigidly attached at its outer periphery to the outer envelope and which is also rigidly attached at its inner periphery to the bore tube. The spider structure is sufficiently flexible in a longitudinal direction to accommodate differential thermal expansion resulting from the differences in temperatures between the bore tube and the outer envelope produced when the laser is energized for operation.

Abstract: A free electron laser for emitting coherent radiation. The laser includes a wiggler magnet for producing a spatially periodic magnetic field in a drift region into which relativistic electrons are injected in a predetermined direction. An axial magnet is provided which generates an axial magnetic field parallel to the above predetermined direction. The axial field is tapered in field strength within a uniform wiggler region, wherein the wiggler field is of uniform and constant magnitude, such that the tapered field acts to oppose the change in axial electron velocity resulting from the free electron laser interaction as electrons travel through the drift region. The tapered axial field acts to enhance power output and efficiency.