Stimulated scattering of light by surface waves under total internal reflection conditions

The gain maxima are found for the stimulated scattering of light by surface waves in the range of large scattering angles. It is shown that the gain maxima appear as a result of formation of glancing (along the boundary) anti-Stokes waves and are due to a reduction in the importance of stray anti-Stokes scattering which is always present because of incomplete spatial phase matching of the interacting waves. A full analytic investigation is made near the gain maxima. The parameters of the incident light beam corresponding to a threshold minimum are obtained. It is shown that the threshold for the scattering through large angles under total internal reflection conditions is approximately an order of magnitude less than in the case when light is incident on a boundary of an optically rarer medium.