Increased efficiency of vacuum ultraviolet generation by stimulated anti-Stokes Raman scattering with Stokes seeding

Stimulated anti-Stokes Raman scattering in molecular hydrogen allows for the generation of continuously tunable narrow-bandwidth radiation down to the transmission limit of vacuum ultraviolet (VUV) window materials. Simultaneous irradiation of UV-pump radiation (in this application, dye laser radiation of wavelength lambda = 372 nm) and of radiation whose wavelength corresponds to the first Stokes component allows a considerable increase in efficiency-by nearly 2 orders of magnitude in the far VUV. The additional Stokes radiation is generated in a simple manner during the passage of the unfocused pump radiation through a high-pressure Raman cell that precedes the VUV Raman cell.