Some regularities in the spectra of inverse Raman scattering

Theoretical and experimental investigations were made of the profile of an inverse Raman scattering (IRS) line in a wide range of pump intensities. Analytic expressions were obtained for the spectral density of the intensity of Stokes and anti-Stokes waves. It was found that an IRS line forms as a result of a complex combination of the Raman and parametric processes. At some value of the pump intensity a maximum appears in the background of an IRS line and initially this maximum is of interference origin. When the IRS threshold is exceeded significantly, the maximum transforms into an anti-Stokes stimulated Raman scattering line. This anti-Stokes line does not prevent the observation of IRS as a result of the same Raman-active transition. The results are reported of an experimental investigation of the 992 cm^–1 line of benzene carried out using one and two cells in a collinear IRS configuration. The results obtained are found to be in qualitative agreement with the theory.