Evidence for nonisochronism of material vibrations in stimulated Raman scattering

Abstract

Evidence is found for a decrease of the Raman shift in stimulated Raman scattering with an increase of the pump intensity, which is interpreted as a manifestation of vibrations' nonisochronism. It is shown that the nonisochronism corresponds to a saturation-type nonlinearity of material vibrations in fused silica and to a Kerr-like nonlinearity in BK-7 glass.