Raman scattering of light by 2LO-phonons

A theory of resonance Raman scattering of light by 2LO-phonons in semicondu ctor crystals is presented. Wannier excitons are considered as intermediate states. Analytic expressions are obtained that take into account contribut ions from different chains of intermediate states. The scattering cross sec tion is shown to be weakly dependent on the wave vector imparted to the pho non system. The theoretical model permits the calculation of the scattering cross section for the energy of the exciting radiation photon below the le vel of exciton resonances. (C) 2001 MAIK "Nauka/Interperiodica".