Abstract: An RF excited gas laser having an optical cavity that is also a resonant cavity in the RF region is improved by the spacing of discrete inductors at fixed points along the cavity so that the problem present in the prior art of nonuniform excitation of the discharge along the cavity is eliminated and the discharge is essentially uniform throughout the cavity volume.

Abstract: An RF-discharge waveguide laser having two parallel waveguides is improved by the addition of coupling channels which permit the plasma in said waveguides to communicate.

Abstract: An RF-discharge waveguide laser incorporates two or more waveguides sharing a common set of discharge electrodes. The device may be used to provide two lasers operating on the same or different frequencies, or a single laser with two waveguides contributing to the power output.

Abstract: An RF-excited gas laser is improved by the addition of an inductor in parallel with a discharge resistance Rg and capacitance C.sub.wg to form a tuned circuit having a resonance frequency such that the real part of the complex impedance of the discharge chamber is matched to the output impedance of a driving oscillator and by the use of an input circuit that compensates for the imaginary part of the discharge chamber impedance.

Abstract: An improved electrode configuration and method for the deposition of electrical power into an electric discharge laser having a gas path transversely disposed to an optical axis and the electric field is disclosed. The electrode configuration includes a cathode, having one or more common geometry rod elements of a thoriated material disposed transverse to a gas path and a planar anode disposed opposite the cathode in a parallel relationship thereto wherein the cathode and the anode define the gas path therebetween. The electrode configuration is adapted for operation without ballast resistance in the electrical circuit and without the utilization of preionization means. The electrode configuration provides a discharge having substantially diffuse and uniform characteristics within the discharge region.

Abstract: A closed cycle chemical laser adapted for continuous wave operation is disclosed. A first gas such as sulphur hexafluoride is decomposed by an electrical discharge means to provide at least some fluorine atoms which when combined with molecular hydrogen in a mixing chamber located upstream of and proximate to an optical power extraction chamber forms an excited laser species capable of stimulated emission to produce a continuous wave output beam. After passing through the optical cavity the effluent is purified by selective absorption and adsorption processes to eliminate the laser species from the effluent and to separate the hydrogen for recirculation back to the mixing chamber. The remaining effluent has its pressure increased, is supplemented with makeup feed gases and is recycled. The operation of the system using sulphur hexafluoride and hydrogen gases is discussed in detail and various combinations of other suitable reactants are disclosed.

Abstract: A method for cavity dumping a Q-switched laser having a gaseous gain medium to obtain submicrosecond output pulses, typically controllably variable between ten and three hundred nanoseconds at a high pulse repetition frequency typically up to at least twenty-five thousand pulses per second is disclosed. In a laser adapted for continuous wave operation, a combination of a retardation element and an electrooptic modulator provides a first polarization state to intracavity radiation incident onto an intracavity polarization coupler oriented to couple out of the cavity radiation having the first polarization state to provide a high loss condition to the cavity to maintain the laser below threshold. A voltage applied quickly to the modulator converts the first polarization state to a second polarization state to provide a low loss condition to the cavity to Q-switch the laser.

Abstract: A laser having a gaseous gain medium capable of continuous wave operation and including an etalon with a Stark active gas disposed therein, adapted for providing submicrosecond pulses is disclosed. A method of utilizing the Stark effect to tune rapidly an etalon to form an output mirror having a variable reflectivity to Q-switch and cavity dump the optical flux within a laser to provide an output pulse of laser radiation having a submicrosecond pulse width, typically variable between fifty and three hundred fifty nanoseconds, at a pulse repetition frequency up to twenty-five kilohertz is disclosed. A laser typically having a carbon dioxide gain medium adapted for continuous wave operation includes a grating defining one end of the laser resonator and an output mirror defining the other end wherein the output mirror is an etalon formed with two mirrors containing a switching cell having a Stark active gas disposed therein.

Abstract: An unstable resonator having high magnification and capable of accommodating an active medium having high gain and small dimensions is disclosed. The unstable resonator, formed with a pair of coupled cavities, has a diffraction grating capable of providing high resolution of the bandwidth of radiation from a high gain medium such as a dye medium and is capable of providing a laser beam with a continuous cross-section having far field characteristics of high quality.

Abstract: A chemical laser having means for repeatedly circulating the gaseous working medium in a portable, self-contained system is disclosed. An excited laser species is formed by chemical means and after passing through the optical cavity, the working medium is purified by selective absorption and adsorption processes, increased in pressure, supplemented with makeup feed reactants and recycled. The operation of a system using deuterium and sulfur hexafluoride gases is discussed in detail although various combinations of other suitable reactants which provide a halogen and hydrogen or an isotope thereof are disclosed.

Abstract: Method and apparatus for providing a large fraction of the energy coupling from an unstable resonator in the central lobe of the far field pattern of the output beam from the resonator are disclosed. The resonator is designed to allow a low order mode pattern to resonate about the optical axis therethrough and radiation is coupled out from both the axial region and the outer region of the mode. The geometry of the systems is formed with transmissive and reflective optics in various configurations of linear and ring lasers.

Abstract: A new resonator concept which is especially useful in chemical laser applications is disclosed. A ring end mirror, a conical folding mirror and a circular end mirror are combined to form an unstable resonator including a radial direction propagation having a gain medium region and a region of axial direction propagation. Alternate embodiments of the invention include the use of nonreflective fins in the region containing the working medium to suppress superfluorescence and an aerodynamic window to keep depleted working medium out of the path of the resonant beam.