Calculations of hyper-Raman tensor components of alkali halides

Calculations of hyper-Raman scattering by the zone-centre optical phonons in NaCl, KCl and KBr crystals based on the bond polarizability approach are presented. The results obtained for the hyper-Raman tensor components are in agreement with experimental data reported previously in literature. A weak cubic anisotropy of the hyper-Raman tensor is found. For the LO mode our results predict the lattice and electro-optic contributions to hyper-Raman scattering to be of the same order of magnitude.