Deviation of the angular distribution in the stimulated Raman scattering from the phase-matching conditions in substances with small Kerr constants

It was established that the angular distribution of the first anti-Stokes component in liquid nitrogen and calcite depended on the power density of the exciting radiation. Near the stimulated Raman threshold the first anti-Stokes component appeared only in the direction of propagation of the exciting radiation but when the stimulated Raman scattering was saturated, it appeared only along the surface of a cone. Additional anti-Stokes cones, which did not obey the phase-matching conditions, were observed for some types of exciting radiation. The appearance of the first anti-Stokes component along the axis was accompanied by the formation of self-focusing points in the field of the first Stokes component at the front of the scattering cell.