Abstract: The invention provides a metal vapor Raman cell structure for laser wavelength conversion and a method for mounting a sapphire window onto a metal tube having a known outside diameter in the manufacture of the aforesaid Raman cell. According to the method of this invention, a sapphire window and a metal tube having a dissimilar coefficient of thermal expansion are mounted and sealed together. The method of sealing the sapphire window onto the metal tube comprises the steps of: (1) cutting a narrow circular groove in one face of the sapphire window; (2) mounting the metal tube into the seat defined by the groove cut into the sapphire window; and (3) disposing a sealing material between the outer face of the seat defined by the groove and the metal tube disposed therein. According to this technique, the sealing material disposed in the groove is placed under compression during the operation of the vapor Raman cell so constructed.

Abstract: High-intensity-discharge sodium lamp incorporates as a starting gas xenon at a pressure between 50 and 300 torrs, in order to improve the lamp efficiency and the spectral power distribution of the discharge. To facilitate lamp starting on a conventional pulse-type starting circuit, a trigger electrode is wrapped about the exterior of the arc tube proximate one of the lamp electrodes, with the potential applied to the trigger electrode during lamp starting being the same as that which is applied to the other or more remote lamp electrode. The starting pulse applied between the trigger electrode and the proximate lamp electrode initiates the lamp discharge. The trigger electrode also extends along the outer surface of the arc tube contiguous therewith toward the other electrode and the discharge, once initiated, progresses toward the other electrode.

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.