Performance data on cadmium and zinc metal vapor arc lamps as efficient light sources for deep ocean waters

The optical attenuation characteristics of deep ocean waters show a broad minimum between 460 nm and 510 nm. Optical sources for underwater applications should emit in this ocean window to minimize the required optical power. To fulfill this need for an efficient source, a new pair of are lamps were developed: zinc-xenon and cadmium-xenon. Performance and engineering data on this type of short-are lamp with various electrode spacings are presented in terms of spectral-emission curves, line widths, electrical characteristics, and conversion efficiencies. Lamp blackening due to the tungsten-water cycle as a limitation to lamp life is discussed. Sample lifetime data indicate lifetimes in excess of 200 hours are realizable.