Abstract

Two- photon resonant four–wave mixing (4-WM) in metal vapors is a useful technique to generate tunable coherent radiation in the VUV region. Harman and Stoicheff extended the wavelength range to 87.5 nm with a Hg vapor [1]. When rare gas is adopted as the nonlinear medium, shorter wavelength generation is achieved, and gas treatment problems in metal vapors can be resolved. The first demonstration of 4-WM in Xe and Kr has been made by Hilbig and Wallenstein [2,3]. The difficulty of 4-WM in rare gas is that the two-photon resonant wavelengths λ₁ are too short to cover them by a dye laser. However, the efficient nonlinear crystal β-BaB₂O₄ has made i t easy to generate λ₁=256 nm for Xe and 217 nm for Kr.

© 1988 Optical Society of America