A semiclassical model of the transverse electro-optic effects including both electronic and ionic contributions is proposed for perovskite materials. It is found that for perovskite structure the linear and the nonlinear susceptibilities are related via a single parameter of the material. Therefore, the model yields a formula that provides a semiquantitative prediction of the quadratic electro-optical coefficient of the materials from their indices of refraction and dielectric constants.

• Received 15 November 1991

DOI:https://doi.org/10.1103/PhysRevB.46.3709