The hyper-raman tensors of the zone-center optical phonons in oxygen perovskites and their relations to other nonlinear optical effects

Abstract

The well-known relations between Raman scattering, three-wave mixing, and the linear electrooptic effect in the transparency region of oxygen-octahedra ferroelectrics are extended to the next higher order of optical nonlinearity. Relations between hyper-Raman scattering, four-wave mixing, and electric-field-induced second-harmonic generation are derived and discussed in detail for SrTiO₃ and KTaO₃ at room temperature.