Abstract: In a slab laser, the optical pumping lamps extend transversely to the mean direction of the laser beam with the spatial period of the lamps being harmonically related to the spatial period of the zig-zag laser beam path within the slab, preferably with equal periods. In addition, the lamps are preferably positioned in registration over the lines of intersection of the central ray of the laser beam with respective broad face of the laser slab. A planar flashlamp reflector is employed for economy of fabrication. Directional lamp reflectors are employed for increasing laser efficiency and performance by discriminating against amplified surface waves.

Abstract: The invention deals with a face pumped slab laser in which the slab is of a rectangular configuration, favoring use of an optical resonator cavity capable of producing a rectangular beam of good quality within the cavity. The novel optical resonator cavity, which produces this rectangular beam, is stable on one axis corresponding to the smaller beam dimension and unstable on an axis orthogonal to the first axis corresponding to the larger beam dimension. The result is both high efficiency, excellent power and a good quality output beam is produced.

Abstract: The generator comprises an envelope and two mirrors defining a resonant cavity, in which is maintained a monolithic wave-guide with a capillary. The capillary is formed in a thinned portion of the guide. Two electrodes extend over the thinned portion of the guide. The capillary is circular in cross section, this being obtained by drilling or extrusion of a cylindrical bar made of dielectric material. The circulation of the laser gas is excellent and the laser plasma uniform. The generator has multiple applications, for example in the medical field.

Abstract: Apparatus for establishing and maintaining a stable electrical discharge across a stream of gas flowing through a gas flow channel, particularly useful in high-power lasers, comprises a plurality of modular elements each including a plurality of electrodes, a ballast impedance for each electrode, and a cooling element for each electrode in thermal communication with the electrode and its ballast impedance, all embedded within a block of insulating material. The ballast impedances for the electrodes at the downstream side of the gas flow channel have lower impedance values than those for the electrodes at the upstream side of the channel so as to compensate for the lower impedance of the gas flowing through the channel at the downstream side and to produce a substantially constant voltage across the various portions of the channels.

Abstract: A combustion driven laser employs HBr as one of a plurality of lasing species. One embodiment of the invention lases simultaneously on the three species HF, HCl, HBr.

Abstract: A waveguide gas laser of improved stability and efficiency resulting from novel improvements. Such improvements, including longitudinal RF excitation, unique ballasting techniques, a novel drive circuit design that is immediately responsive to defeat unstable hot spot problems, and a controlled power excitation function, result in an RF excited waveguide gas laser that substantially overcomes disadvantages of prior art devices.In one embodiment the invention consists of a longitudinally excited RF waveguide laser in which the spacing geometry of the electrodes is variable independently of the waveguide chamber geometry resulting in increased performance efficiency. In addition, hot spot problems are eliminated or substantially reduced by capacitive ballasting achieved through novel structural configurations including electrodes that are isolated from the waveguide chamber by means of a suitable dielectric spacing medium such as ceramic or aluminum oxide.

Abstract: A gain-expanded free electron laser in which a relativistic electron beam exchanges energy with an electromagnetic wave in an interaction region defined by a magnet system is configured to suppress betatron excitation. The magnet system, the electromagnetic wave, and electron beam are characterized by a net optical phase slip qL during the interaction between the phase of the electromagnetic wave and the phase of the electron transverse velocity, and a net betatron phase advance .LAMBDA.L. The optical phase slip and the betatron phase advance are chosen to satisfy the following constraints.vertline.qL.vertline.=K.pi..vertline.qL-.LAMBDA.L.vertline.=M2.pi.where K is an integer and M is a positive integer. These constraints suppress the excitation of the betatron motion that is excited during the pass of the electrons through the interaction region.

Abstract: An acousto-optic time integrating two-dimensional frequency scanning correlator for cross-correlating signals which are separated in frequency. Two coherent light beams which are derived from the same laser are fed across respective Bragg cells, one cell having the signal A(t) cos .omega..sub.A t propagating thereacross and the other cell having the signal B(t) cos .omega..sub.B t propagating thereacross. The respective output beams are comprised in the x direction and expanded in the y direction and are made incident on an acousto-optical correlator device having chirp signals counter-propagating thereacross. The optical output is fed to a time-integrating photodiode array which provides an output signal corresponding to the cross-correlation of A(t) and B(t). In a further embodiment, the two Bragg cells are replaced by a single Bragg cell and beams having different polarizations are fed thereacross.

Abstract: A long rare-gas halide excimer light source excited by a capacitively coupled discharge pumps a dye laser with high efficiency in a configuration matched to the length of the discharge.

Abstract: An acousto-optic deflector having a plurality of transducers formed on a planar surface of the acousto-optic medium wherein the incident laser beam is maintained at the Bragg angle as the deflection angle is changing by utilizing electronically introduced phase delays between adjacent transducer electrodes.

Abstract: The electrodes of a electro-optic device having a flexible electrode bearing member, such as a silicon integrated circuit, are re-contoured as required to generally conform to the mating surface of the electro-optic element by resiliently biasing the electrode bearing member against that surface. The bias is suitably supplied by a compressed elastomeric pressure pad which underlies the flexible electrode bearing member. The pressure pad is substantially coextensive with the electrode bearing portion of the flexible member so that a more or less uniform bias is applied throughout that area.

Abstract: A thick film line modulator/scanner (50) for use in an electro-optic line printer (14). A light valve utilizes a thin electro-optic layer (212) with the index of refraction of the layer being higher than the neighboring material so that the light can be guided in it. A laser beam (48) is focused into the layer, the beam expanding sideways so that a sheet of collimated light is provided. This light is affected by an array of electrodes (240, 242), consisting of an extended set of individually addressed metal fingers (240) on one side of the film (212), and a broad electrode (242) on the other side of the film. This broad electrode could also be segmented to the individually addressed electrodes. The light diffracted by this electrode set is reimaged onto the recording medium (14) with the zero order diffracted light blocked out, so that each electrode acts as a light modulator for one picture element on the output.

Abstract: A single element interposed in a laser resonator cavity provides for AM mode-locking, Q-switching and dumping in a sequential operation in which a Pockels cell or like polarization rotation device is first energized to prevent build-up of radiation in a laser cavity, is then switched to provide for mode-locking by energization with a periodically varying signal, and is finally energized to dump a single mode-locked pulse. The sequential operation permits the use of a single electro-optic element and a single pair of electrodes. Q-switching, mode-locking and dumping are accomplished utilizing the same physical effect in the crystal, e.g., polarization rotation.

Abstract: In a gas laser tube including a laser capillary tube having one fixed end secured to the envelope surrounding the capillary tube and one free end. A support structure for the free end comprising a discharge diverting tube extending from the envelope toward and overlapping the free end of the laser capillary tube and a coil spring interposed between the free end portion of the laser capillary tube and the inner wall of the discharge diverting tube. The free end portion of the capillary tube is supported resiliently by the coil spring and the capillary tube is kept straight without bending or vibrating while absorbing the elongation of the capillary tube caused by thermal expansion.

Abstract: A light modulator/deflector which uses acoustic surface waves wherein an illuminating beam 10 enters the side of and strikes the active surface 18 of a transparent and electrooptic acoustic substrate 12 near the grazing angle of incidence and is reflected off that surface 18 through the remaining portion of substrate 12 and out the other side thereof into at least a zero order undiffracted direction and a first order diffracted direction. The light 10 is collimated so that it interacts with as much of the acoustic wave 20 as possible. A set of interdigital electrodes 16 is evaporated on this surface 18 so as to launch acoustic waves 20 in a direction normal to the plane of incidence of the light. Along the path of the travelling acoustic wave in the same substrate are placed one or more repeater acoustic wave sources 72, 74 to boost the decaying acoustic wave 62 back to its original power level.

Abstract: Improved laser system gain is achieved by using Gadolinium to totally replace the Yttrium in a Lithium Yttrium Fluoride (YLF) host crystal so as to increase the amount of Neodymium which can be doped into the host crystal.

Abstract: Apparatus and method for a simple low cost gas laser tube wherein exhaust of the tube is accomplished by exhausting gas through spaces formed between a total reflection mirror and cylindrical support structure for the mirror mounted at one end of the tube to an exhaust pipe connected to the cylindrical structure and sealing said exhaust pipe.

Abstract: The optical beam scanner employs novel utilization of the well known Stark effect. By means of an external applied voltage, a change in the index of refraction of an optical medium is produced. This produces a bending effect on light transmitted through the medium. Varying the applied voltage can be used to vary the refractive index, or a refractive index gradient may be produced by providing a gradient in the applied field, to produce no moving parts scanning of the optical beam.

Abstract: A device for translating the frequency of the energy contained in a laser beam. Higher order Raman scattering is utilized to convert the energy in a laser beam into a collimated beam of radiation at a frequency removed from that of the original beam by an amount corresponding to the frequency shift exhibited by higher order Raman scattering processes. A Raman cell is utilized as a saturated amplifier at power density levels below that required for oscillation, so as to obtain efficient conversion. By selecting the path length within the Raman cell, nearly all of the energy exiting the cell is caused to appear in a single, higher order Stokes wave.

Abstract: A closed cycle, high repetition pulsed laser having a laser flow channel with an annular flow return surrounding the laser flow channel. Ultra high vacuum components and low out-gassing materials are used in the device. An externally driven axial flow fan is used for gas recirculation. A thyratron-switched low-inductance energy storage capacitor is used to provide a transverse discharge between profiled electrodes in the laser cavity.