Abstract: A plurality of spaced-apart apertured discs constructed of electrical insulator material, are sealed within the quartz tube structure of a metal halide laser tube to increase the path length along the wall of the laser tube between the discharged electrodes to constrain the discharge to the central gaseous core rather than along the wall of the quartz tube. The use of electrical insulator apertured discs sealed with the laser tube of a metal halide laser facilitates the utilization of the halide species as the laser medium.

Abstract: A double sealed technique in an evacuated quartz jacket produces an electrical feedthrough assembly suitable for use in sealed-off, pulse, longitudinal discharge lasers compatible with operating temperatures of up to 1100.degree. C. without oxidation and with a minimum of circuit inductance.

Abstract: Shifted Raman radiation for an all-hot Raman discharge cell is produced by external laser pumping of a metal halide medium in the cell during an afterglow period following dissociation of the metal halide medium into metal atoms and before recombination to form the original species of the metal halide medium.

Abstract: A quartz laser tube for use with a metal, or metal halide, laser media employs a coaxial electrical connection in which a longitudinal discharge in the laser medium serves as the central conductor, and the ground return path is a cylindrical metal container which surrounds the laser discharge. This arrangement minimizes the circuit inductance for a given longitudinal discharge, and the outer metal cylinder serves both as a heat shield and a ground shield for reducing electrical noise radiation. Optical access in the longitudinal direction is provided by cylindrically-symmetrical electrode/window assemblies attached to either end of the quartz laser discharge tube.

Abstract: The low temperature operation, i.e., between 300.degree. and 500.degree. C, of a bismuth halide vapor laser avoids the formation of the metal dimer Bi.sub.2 the occurrence of which in the operation of a pure bismuth laser significantly reduces the gain and stimulated output due to absorption of the laser energy. The successful operation of a bismuth halide laser provides the basis for developing a laser operating in the underwater transmission band of between 4,700 and 4,800 Angstroms which lies near the minimum of the sea water absorption scattering curve thus rendering it a prime candidate for underwater applications.

Abstract: High-intensity arc-discharge (HID) device of the metal-halide additive type incorporates as essential discharge-sustaining constituents mercury and inert ionizable starting gas and also sodium and/or lithium iodides and/or bromides as well as scandium iodide and/or bromide. The molar ratio of alkali metal halide to scandium halide is from about 1.7:1 to about 5:1 and this greatly enhances the device efficacy for the generation of visible light, which can be enhanced by as much as 32 percent.