Investigation of the self-focusing of light scattered in the stimulated Raman effect at different excitation levels

An investigation was made of the dependence of the self-focusing of the light scattered in the stimulated Raman effect on the power of the pulse of the first Stokes component. The investigation was carried out on substances with different values of the Kerr constant: These substances included liquid nitrogen, calcite, carbon disulfide, and nitrobenzene. It was found that the self-focusing of the scattered light was always observed, even if the exciting radiation was not self-focused. The distributions of the self-focusing points near the front and rear ends of a sample were similar, if the scattering layer was thin and the power density of the exciting radiation was low. An increase in the power density of the first Stokes component resulted in an increase of the self-focusing points and a reduction in their diameter. The maximum power density at the self-focusing points was a constant characteristic of a given substance.