Aspects of wave propagation in a nonlinear medium: birefringence and the second-order magnetoelectric coefficients

Abstract

Magnetoelectric materials have the interesting property of exhibiting polarization induced by a magnetic field or magnetization induced by an electric field. As a consequence, a multitude of effects can be produced by means of controllable external fields. A general method for deriving phase velocities and its corresponding polarization vectors for light rays in nonlinear optical materials is here revisited and used to study wave propagation in a second-order magnetoelectric medium. Particularly, birefringence effect is theoretically examined and it is shown that it can be used as a tool to obtain most of the second-order magnetoelectric coefficients \(\beta_{ijk}\) of a material having an isotropic linear sector. Some optical properties of nonlinear materials presenting a natural optical axis are also discussed.