Dependence of rotational and vibrational Raman scattering on focusing geometry

Stimulated rotational and vibrational Raman scattering in H/sub 2/ was investigated with a circularly and a linearly polarized XeCl laser beam and the influence of the focusing geometry on the threshold for rotational and vibrational scattering, respectively, was studied. It is shown that with a circularly polarized pump beam a high-angle focusing geometry allows to get only rotational Raman scattering, whereas a low-angle focusing geometry provides only vibrational Raman scattering for gain suppression effects.