Rotational Raman scattering dependence on pump polarization

The influence of the ellipticity degree of the pump radiation polarization on threshold energies and energy conversion efficiencies of stimulated rota tional Raman scattering (SRRS) an investigated in H-2 With a XeCl excimer l aser, by using different focusing geometries. For the first time, it is sho wn that the dependence of SRRS on pump radiation polarization is also affec ted by the focusing geometry, i.e. whether low- or high-angle focusing is a pplied. The experimentally determined threshold energies as a function of t he pump radiation polarization are in accordance with theory mainly at high -angle focusing geometries. It is also shown for the first time that gain s uppression effects on vibrational Raman scattering have to be considered in understanding the experimental results.