Abstract: An electrical excitation circuit is disclosed for a gas laser. The electrical excitation circuit includes a charging circuit connected in series with a pulse forming network between a power source and the laser load. The charging circuit includes a capacitor charged by the power source and a thyratron for transferring voltage to the pulse forming network. Alternatively, the charging circuit includes a capacitor charged upon the firing of a silicon controlled rectifier through a saturable step-up transformer which saturates for transferring voltage to the pulse forming network. The pulse forming network includes a saturable inductor switch positioned with respect to a capacitor so that when the voltage on the capacitor reaches a predetermined level, saturation of the saturable inductor switch releases electrical energy stored in the capacitor to the laser load.

Abstract: The output power and efficiency of a gas discharge laser is substantially improved by the substitution of neon (Ne) for helium (He) as a buffer in the lasing medium. One embodiment of the invention is a pulsed excimer laser having a lasing gas comprising a mixture of krypton (Kr) and fluorine (F.sub.2). Use of Ne with the KrF excimer lasing medium further enables advantageous utilization of corona wire pre-ionization to initiate the main discharge of this type of laser.

Abstract: An optical resonator assembly mounted externally on a hermetically sealed gas transport laser comprises a U-shaped tubular bench secured to the laser housing top wall and having an elongated beam with legs extending at right angles to opposite ends, respectively, of the beam adjacent to the front and rear walls of the laser housing. Flat bases depend from the respective bench legs and overlay optical windows in the front and rear housing walls through which the internally generated laser beam passes. The bases have openings aligned with the windows, respectively, and adjustably mount mirror support plates, respectively, adjacent to those openings. Mirrors attached to the support plates define the laser optical cavity. The bench is a rigid tubular structure providing stable support for the optical components and also constituting a fluid conduit for carrying cooling air to minimize thermally induced dimensional changes.

Abstract: A physically compact gas transport laser operable at high pulse rates (greater than 1 kHz) in a high vacuum (greater than 10.sup.-5 Torr) is achieved by flowing the active gas at high velocity (greater than 50 m/sec) between two discharge electrodes in a hermetically sealed housing containing squirrel cage type blowers, a heat exchanger and the laser electrodes. A pulse forming network and blower motors are mounted externally of the housing as is the optical resonator assembly. A central partition divides the housing interior into upper and lower gas flow channels. The blowers are located in the lower channel at the housing end downstream from the electrodes and are rotatable in a plane parallel to the plane of the partition. The heat exchanger is located at the opposite end of the housing and both cools and stabalizes the flow of the circulating gas.

Abstract: An electrode assembly for a compact high vacuum pulsed gas discharge laser comprises an elongated cathode and a coextensive anode spaced apart in a direction transversely of the flow of gas to define a discharge gap. Each of the electrodes is connected at a plurality of equally spaced points along its length to a like number of conductive rods which extend through the top wall of the laser housing for connection to a power source. The cathode comprises a carrier bar directly attached to said rods and a cathode bar adjustably secured to the carrier bar for vertical movement toward and away from the anode to permit attainment of a uniform discharge gap throughout the length of the electrodes. Preionization of the discharge gap is achieved by means of a conductive sleeve electrically connected to one of the electrodes and disposed against the inner surface of a dielectric tube which contacts the other electrode throughout its length.

Abstract: An apparatus for initiating electrical discharge in a gas transport laser having two or more sets of electrodes comprises a pulse generator connected to both sets of electrodes. The pulse generator comprises an alternating current (AC) source connected to the primary windings of two transformers having secondaries connected to the sets, respectively of electrodes. By energizing the transformers after the application of a direct current (DC) voltage across the electrodes of each set, a discharge across the sets of electrodes occurs simultaneously for a balanced starting of the lasing action.The invention also comprehends the method of starting a laser having a plurality of sets of electrodes consisting of the steps of applying a DC potential across each set of electrodes and transmitting at least one voltage pulse simultaneously to one of the electrodes of each set to produce simultaneously an electrical discharge between all sets of electrodes.

Abstract: Continuous wave (CW) output power from a gas transport laser is substantially increased by disposing a plurality of parallel cylindrically tubular cathodes in the main stream transversely of the direction of gas flow and spaced above a coextensive segmented anode in the opposite wall of the channel. Ballast resistors are connected between the cathodes, respectively, and the power supply to optimize the uniform arcless distribution of current passing between each cathode and the anode. Continuous output power greater than 3 kw is achieved with this electrode configuration.

Abstract: Continuous wave (CW) output power from a gas transport laser is substantially increased without arcing by the use of a tubular cathode having a racetrack-shaped cross section and disposed in the main stream of gas flow through the laser channel transversely of the direction of flow and spaced above and upstream from a coextensive segmented anode in the opposite wall of the channel. The racetrack-shaped cross-sectional configuration of the cathode provides maximum electrode surface for generating a glow mode electric discharge and also induces turbulence at that surface so as to support high current densities without arcing. Continuous output power greater than 3.5 KW is achieved with improved efficiency with this electrode configuration.