Abstract: The disclosed laser employs a working gas comprising ammonia and a buffer gas which is chemically non-reactive with ammonia. A pumping laser beam at a wavelength of 9.2 .mu.m, provided by a carbon dioxide laser tuner to the R(30) transition of the 001-020 band, irradiates the working gas to excite ammonia molecules from the symmetric ground state to the anti-symmetric .nu..sub.2 =1 vibrational manifold. Collisions with buffer gas molecules cause the excited ammonia molecules to undergo intra-molecular energy transfer to a plurality of energy levels in the symmetric .nu..sub.2 =1 vibrational manifold. Laser oscillation is achieved simultaneously on a plurality of .nu..sub.2 =1 to ground transitions in the wavelength range extending from about 9.3 .mu.m to about 13.8 .mu.m.

Abstract: The disclosed arrangement for enhancing the starting characteristics of a cold cathode gas laser includes a strip of electrically conductive plastic disposed on the outer lateral surface of the laser tube. The strip extends longitudinally along the tube for most of the length of the tube and extends circumferentially about the tube in the vicinity of its end remote from the laser anode. A tape of electrically insulating material overlies the strip and adhesively holds it against the laser tube. The end of the strip remote from its circumferentially extending portion is electrically connected to the anode. Faster starting with relatively low voltages and with a more uniform voltage magnitude and turn-on time delay for individual laser tubes are achieved.

Abstract: A circuit is disclosed for impedance matching an electrical signal-generating transducer to an electrical signal-processing amplifier while substantially retaining both the original signal-to-noise power ratio and the original signal amplitude at the input to the amplifier. A load resistance of a value substantially equal to twice the characteristic resistance of the transducer is coupled across the amplifier input, while a negative low-noise resistance approximately equal in magnitude to the source resistance is coupled in series with the load resistance. A transmission line having a characteristic impedance approximately equal to the transducer resistance is coupled between the transducer output and the series-coupled load resistance and negative resistance.

Abstract: Arrangements are disclosed for reciprocatively scanning a focused laser beam across an optical frequency converting crystal while deriving an output laser beam at the converted frequency along a stationary path. An effective elongated illumination pattern is provided for the crystal which reduces thermal gradients across the crystal, while the beam density at the crystal is sufficiently large so that high conversion efficiency may be realized.

Abstract: Waveguide lasers are disclosed which are excited by means of a tranverse discharge at rf frequencies generally in the vhf-uhf range, i.e., from about 30 MHz to about 3 GHz. These excitation frequencies are sufficiently high to ensure negligible interaction of discharge electrons with the discharge-establishing electrodes, thereby achieving superior discharge properties which result in a laser of improved performance and reduced size and complexity.

Abstract: Arrangements are disclosed for substantially reducing the effect of the inherent transducer capacitance in a transducer-coupled electromechanical system which is subject to vibrational movement. Electrical circuitry is coupled across the transducer output to provide a negative capacitance having a magnitude substantially the same as that of the inherent transducer capacitance, thereby substantially nullifying the inherent transducer capacitance and enabling improved damping (including low-noise damping) to be achieved.

Abstract: Lasers are disclosed wherein trapped multiline laser radiation from a DF laser is employed to pump a DF-CO.sub.2 working gas mixture within the optical resonator for the DF laser. The multiline pumping energy is resonantly absorbed by the DF component of the working gas mixture and collisionally transferred to upper energy levels of lasing transitions in CO.sub.2. A narrow-band optical resonator disposed about the working gas interaction region with the pumping radiation and tuned to a desired CO.sub.2 transition enables a single line laser output to be obtained on the desired transition.

Abstract: Apparatus for delivering a plurality of balls one after another with spacing therebetween to a desired location for use by a player. The apparatus includes a support mounted on a surface which may be vertically adjustable and a gravity feed ball supply for permitting a plurality of balls to feed by gravity onto the playing surface. A gate is provided which retains one ball in position until another is released. The apparatus may include a movable member which is connected to the gate and down which a ball moves under gravity. When the ball is discharged onto the playing surface after it leaves the movable member, a counterweight also connected to the gate restores both the gate and the movable member to a position whereby the gate releases a subsequent ball while the movable member assists in blocking more than one ball from moving past the gate.

Abstract: A laser internal coupling modulation arrangement is disclosed wherein a wire grid polarizer serves as one of the reflectors forming part of the laser optical cavity, as a polarization selector which constrains the laser oscillation to a desired linear polarization, and as an output coupler which couples an orthogonal linearly polarized beam out of the laser optical cavity in response to an amplitude varying modulating signal applied to an electrooptic modulator disposed within the laser optical cavity.

Abstract: An optical frequency doubling arrangement is disclosed in which the indices of refraction of light in a frequency doubling electro-optic crystal are controlled by both electric field pulses applied across the crystal and heater control pulses for controlling the temperature of an oven in which the crystal is mounted. Both the electric field pulses and the heater control pulses have a duty cycle determined by the detected optical power output from the crystal at the desired double frequency, the heater control pulses being responsive to the measured oven temperature as well. The arrangement is especially suitable for doubling the frequency of 1.06 .mu.m laser beams.

Abstract: Series and shunt flashlamp triggering arrangements are disclosed wherein an electrically conductive patch is intimately bonded to a portion of the outer lateral surface of the flashlamp housing extending over a portion of the high voltage electrode and terminating at a longitudinal location along the housing substantially aligned with the inner end of the high voltage electrode. An electrically conductive wire connected to the patch extends along the outer lateral surface of the housing from the patch to at least the vicinity of the other electrode. The high voltage electrode defines a sharp-edged annular rim projecting outwardly from its lateral surface adjacent its inner end.

Abstract: Frequency discriminators are disclosed employing a crystal filter having a predetermined voltage versus frequency characteristic including a discriminator operating portion slightly below the filter lower cutoff frequency along which the voltage varies substantially linearly as a function of frequency. Detector circuitry rectifies the output voltage from the crystal filter, while voltage level shifting circuitry algebraically combines the output voltage from the detector with a dc voltage such that the algebraic sum of the dc voltage and the detector output voltage is zero when the instantaneous frequency of the input signal to the discriminator is at the discriminator center frequency. The discriminator is constructed without the use of any crystal resonator having a series resonant frequency within the discriminator passband; hence spurious series resonances occur outside of the discriminator passband, thereby facilitating wideband operation.

Abstract: In the disclosed attenuation arrangement a plurality of axially extending boron nitride support rods having a substantially rectangular cross-section are disposed about the peripheral surface of a helical slow-wave structure. An attenuating coating is provided on the substantially radially extending opposing lateral surfaces of each rod, with the substantially circumferentially extending opposing lateral rod surfaces being free from attenuating material.

Abstract: A passive laser Q-switch cell is disclosed wherein a chamber containing a liquid Q-switching material has an extent along the laser beam path not greater than approximately 0.25 mm. When the laser beam has a frequency of approximately 1.06 .mu.m, the Q-switching material may consist of a substantially saturated solution of the dye complex bis(4-dimethylaminodithiobenzil)nickel in toluene.

Abstract: A coupled cavity traveling-wave tube is disclosed wherein each interaction cavity has an oblong configuration in a plane perpendicular to the tube axis. The oblong cavities have a length-to-width ratio of a predetermined value between about 1.2 and 1.6, preferably being about 1.5. Coupling apertures in the end walls separating adjacent interaction cavities extend circumferentially about half way around aligned circular electron beam holes along the tube axis, with the circumferential extremeties of the coupling apertures lying substantially parallel to the length of the oblong interaction cavities.

Abstract: A laser beam frequency modulation demodulator is disclosed utilizing the highly linear frequency versus voltage characteristic of the absorption resonance provided by a Stark-effect cell. An error signal, generated by dither modulation of the Stark-effect cell voltage, is fed back to the Stark-effect cell via a low-pass filter to cause the absorption resonance to track the instantaneous frequency of the laser beam. The feedback signal applied to the Stark-effect cell has an amplitude proportional to the frequency modulation on the laser beam.

Abstract: A coating consisting of polycrystalline Sm.sub.2 O.sub.3 powder dispersed in a Na.sub.2 SiO.sub.3 or K.sub.2 SiO.sub.3 binder may be provided on either the inner or outer lateral surface of a substantially tubular pumping cavity housing member for a Nd:YAG laser. The coating is absorptive of radiation at the lasing wavelength of about 1.06 .mu.m and has a thickness sufficient to provide a high diffuse reflectivity for pumping radiation.

Abstract: A high power, cw, high pressure, electrically excited flowing gas laser is disclosed wherein a laser excitation transverse to the direction of gas flow is initiated by a uniform electron beam perpendicular to the gas flow direction. Laser gas supplied to a plenum chamber at a pressure substantially greater than atmospheric pressure is conditioned by a perforated plate nozzle to flow through the laser cavity in a uniform stream at the desired subsonic velocity. A variable angle diffuser is provided downstream from the laser cavity to decelerate and compress the laser gas before exhausting it into the ambient atmosphere such that at the downstream end of the laser excitation region the laser gas is maintained at a pressure slightly lower than atmospheric pressure.

Abstract: Laser arrangements are disclosed wherein a plurality of individual laser beams at slightly different wavelengths are generated in respective capillary bore waveguides in a common body of dielectric material. The generated laser beams are caused to converge upon a preselected intersection point, either by constructing the bore waveguides with converging longitudinal axes or by deflecting the generated laser beams into the desired converging paths by means of an optical prism. A diffraction grating is positioned at the laser beam intersection point to combine the respective laser beams emitted from the bore waveguides into a composite beam along a coincident path.

Abstract: In the disclosed electron gun positive ions generated by a hollow cathode plasma discharge in a first chamber are accelerated through control and shield grids into a second chamber containing a high voltage cold cathode. These positive ions bombard a surface of the cathode causing the cathode to emit secondary electrons which form an electron beam having a distribution adjacent to the cathode emissive surface substantially the same as the distribution of the ion beam impinging upon the cathode. After passing through the grids and the plasma discharge chamber, the electron beam exits from the electron gun via a foil window. Control of the generated electron beam is achieved by applying a relatively low control voltage between the control grid and the electron gun housing (which resides at ground potential) to control the density of the positive ions bombarding the cathode.