Abstract

High prf discharge rare gas halide (RGH) lasers have continued to advance as efficient high average power sources in the UV.¹ This paper will describe ongoing work with the Closed Cycle Test Bed high prf RGH laser at LLNL, The operation of this device in its original UV-preionized configuration has been described in Refs. 2 and 3. Briefly a maximum XeCl (308-nm) average power of 55 W was produced at 600 Hz, and a power lifetime result of 4 h at 40 W was achieved for operation at ~500 Hz. Fresh gas purge flow across the optical windows was used to prevent the deposition of reflective coatings on the windows during long runs. High resolution plots of the laser energy prf dependence exhibited detailed structure which can apparently be attributed to acoustic resonances in the flow loop. It is believed that the density fluctuations associated with the acoustic oscillations impair the discharge stability and thus decrease the high prf laser energy.

© 1981 Optical Society of America