Stimulated rotational Raman conversion in H/sub 2/, D/sub 2/, and HD

Stimulated rotational Raman conversion has been efficiently demonstrated in all three molecular hydrogen isotopes with a 532-nm Q-switched pump source. Optimum gas pressures and pump focusing have been determined. Single pass conversion efficiencies of 80%, 75%, and 65% have been achieved at the first Stokes wavelengths with H/sub 2/, D/sub 2/, and HD, respectively. The maximum efficiency is generally limited by further Raman conversion of the initially generated Stokes light. The thresholds were found to increase in the order H/sub 2/>