NONLINEAR RAMAN-SCATTERING IN II-III2-VI4 COMPOUNDS

The paper presents an experimental substantiation of the theory (based on the optical vibration anharmonism) of non-linear Raman scattering (RS) in defective II-III2-VI4 compounds. In the transparency region of those compounds the anharmonicity assures processes of direct photon- phonon interaction resulting in the independence of RS characteristics upon the free carrier concentration. When the laser quantum energy ap proaches the band gap E(g) an effective thermalization of the absorbed radiation takes place which in one's turn gives rise to the anharmoni c generation of two or more phonons by a laser photon. These phenomena are shown to result in a non-linear dependence of the RS intensity up on the laser beam power.