Angular structure of higher components of stimulated Raman scattering of light

A brief critical review is made of theoretical papers explaining the ring-like angular structure of the anti-Stokes (α) and second Stokes (ss) components. A simple qualitative analysis is made of this structure on the assumption of constant laser pump (L) and first Stokes (s) components; the s field is regarded as a Gaussian packet of uncorrdated plane waves and the L field is described by a TEM₀₀ wave. It is shown that: 1) the angles of emission of the α and ss components in the case of considerable divergences of the L and s fields, respectively, may be twice as large as the angles deduced from the usual phase-matching conditions; 2) there is no "Cherenkov" radiation when the dimensions of the sample are limited to the cross section of the pump beam.