VUV generation by frequency mixing in a mercury beam

Abstract

The generation of coherent VUV laser radiation by two-photon resonant sum and difference frequency mixing (SFM and DFM) in a free jet of mercury is reported. Using a slit nozzle we obtain about 10 9 photons per pulse in 16 ns at the SFM wavelength of 1251 Å at a total input energy of 0.1 mJ at 3127.5 Å and about 0.9 mJ at 6255 Å. The conversion efficiency turns out to be similar to that of a Hg heat pipe. The addition of rare gas into the expansion chamber of the jet offers the possibility to manipulate significantly the VUV intensity and to estimate in a first approximation the density of the Hg jet, too. Furthermore it hints at different physical processes of SFM and DFM. Finally some applications of this VUV light source for ionization experiments are discussed.