A high repetition rate ion laser spanning the 195-225 nm spectral region

This paper describes the construction and operation of a water-cooled noble gas ion laser which generates average powers of the order of a milliwatt at 5 strong transitions between 195 and 225 nm. This pulsed laser has been operated at repetition rates up to 200 Hz and has produced average powers up to 5.1 mW at 219.2 nm. The pressure and voltage dependence of output power, along with preionization effects, gain, saturation intensities, and the effects of discharge current pulse length are discussed. The optical pulses can be precisely synchronized with respect to an electrical reference signal, and the laser operates at all wavelengths with Brewster windows, permitting convenient interchanging of resonator mirrors. This device has been designed for use as an ultraviolet illuminator in a photoelectron microscope.