Abstract

Recent studies of high resolution VUV spectra of Xe₂, and Kr₂, and Ar₂ produced in supersonic jets have yielded molecular constants and potential energy curves for the ground and first three excited states of these dimers. Lifetimes of the Al_u states were measured and found to vary significantly with vibrational quantum number for Ar₂, and to a lesser extent for Kr₂ and Xe₂. Following this work, an electrical discharge plasma created within the jet was expanded supersonically to populate low vibrational levels of the Al_u and ${\text{BO}}_u^{+}$ states. This proved to be an efficient method for producing population inversion in Ar₂, as confirmed in single-pass gain measurements of ~3 cm^-1 at 126 nm. A cavity with Al + MgF₂ mirrors (80% reflectivity) gave an output of 0.3 mJ through a 0.5-mm aperture in the front mirror. Preliminary experiments with a discharge using neon have resulted in stimulated emission at~71 nm.

© 1989 Optical Society of America