Abstract: A silent discharge gas laser comprises an earthing electrode and a high voltage electrode whose discharge surface is covered with a dielectric and a power source for applying an AC high frequency high voltage to excit a laser gas. The power source periodically and intermittently applies high frequency voltage to turn on and off to give high peak value.

Abstract: A discharge device (10) is disclosed which is capable of providing preionizing ultraviolet wave length photons to the area of a gap between the first (15) and second (35) electrodes of the device. The first electrode (15) includes a core (20) of dielectric material, a conductive plate (23) mounted on one surface of the core, and a conductive grid (26) mounted on an opposed surface of the core which faces the second electrode. The application of a negative voltage pulse to the grid (26), while the plate (23) is maintained at substantially ground potential, causes electrons to discharge between the conductors of the grid and the adjacent surface of the dielectric core, and, in doing so, generates photons having wavelengths in the ultraviolet range. The ultraviolet photons, which are emanated in a two dimensionally uniform pattern over the surface of the dielectric core adjacent the grid, cause ionization of the gas within the main discharge gap between the first and second electrodes.