Abstract

We have recently demonstrated¹ a 7.5% efficient near-diffraction-limited coherent VUV source operating at ~130 nm. The VUV wavelengths are obtained by two-photon resonant four-wave mixing in Hg vapor. The high energy conversion efficiency results from mixing very high quality collimated single-mode laser beams over 1-m interaction lengths. The collimated geometry is very important because it allows tractable modeling, area scaling of the process to higher energies, and high optical quality of the output wave. Output VUV energies exceeding 1.25 mJ/pulse in 8-mm diam beams have been obtained. The VUV wavelength is tunable from 120 to 140 nm by adjusting the pump wavelengths for proper index matching conditions.

© 1989 Optical Society of America