Generation of coherent extreme ultraviolet and vacuum ultraviolet radiation using pulsed nozzles

Abstract

We describe the application of pulsed free jets for the generation of the third harmonic of laser radiation. Using a supersonic expansion of Xe we have frequency tripled an 18 MW beam at 354.7 nm to obtain 5 x 1011 photons/pulse at 118.2 nm, while for CO we have obtained 1 x 1012 photons/pulse at 98.5 nm for an input power of 2 MW at 295.6 nm. In the latter case the conversion efficiency is enhanced by a two-photon resonance via the CO A1 II state. A simple model is outlined for third harmonic generation in a free jet, and the predictions of this model are tested against experiment. © 1984 SPIE.