An efficient, high-power F/sub 2/ laser near 157 nm

Experimental results are presented which demonstrate scaling of an electron-beam-excited molecular F/sub 2/ laser operating near 157.5 nm in mixtures of high-pressure He and a few torr of F/sub 2/ to high powers (7 MW/sq cm unfocused) and high intrinsic efficiencies (3.5%). Results of a parametric study of laser and fluorescence efficiency vs. He and F/sub 2/ pressures are also given, along with measurements of sidelight saturation which indicate 30% saturation of the excited medium by the F/sub 2/ laser photons. A model is described which quantitatively accounts for the observed fluorescence efficiency.