Gas and Solid‐State Lasers Operate in the Ultraviolet

Continuing attempts to discover laser action in short‐wavelength regions have succeeded with both gas and solid‐state lasers. Roy Paananen of the Raytheon Research Division, Waltham, recently reported that continuously operating uv ionized‐gas lasing had been demonstrated over four transitions in three of the noble gases [Appl Phys. Letters 9, 34, (1966)]. Solid‐state semiconductor lasers emitting in the ultraviolet use zinc sulfide and zinc oxide. The zinc‐sulfide model made by Charles Hurwitz of the MIT Lincoln Laboratory, has a peak output power of 1.7 W and a power efficiency of 6.5% [Appl. Phys. Letters 9, 116, (1966)]. The zinc‐oxide laser reported by Frederick Nicoll of RCA Laboratories, Princeton, although less efficient, is the first solid‐state laser to emit in the uv region [Appl. Phys. Letters 9, 13, (1966)].