Abstract

It has been well established for some time that high-pressure transverse-discharge-pumped excimer lasers (among others) require some form of preionization to attain a uniform volumetric discharge. We report the results of a direct comparison between the two leading preionization techniques, namely, photoionization at UV and x-ray wavelengths. The laser used for this test was a 1-J/pulse XeCl excimer laser which was originally equipped with a UV arc preionizer, consisting of a carefully designed spark array behind a transparent screen electrode. This provided highly uniform UV preionization within the discharge volume. For the comparison test, an x-ray transparent window was added to the laser head so that an external x-ray generator could be used.

© 1983 Optical Society of America