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

TL;DR

This paper investigates wave propagation in nonlinear magnetoelectric media, focusing on birefringence and second-order magnetoelectric coefficients, providing theoretical insights and estimates for these effects in specific optical materials.

Contribution

It introduces a method to derive phase velocities and polarization vectors in nonlinear magnetoelectric media, enabling the extraction of second-order magnetoelectric coefficients from birefringence measurements.

Findings

Birefringence can be used to determine second-order magnetoelectric coefficients.

Theoretical estimates of birefringence effects in specific materials are provided.

Optical properties of nonlinear materials with a natural optic axis are discussed.

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 method for deriving phase velocities and its corresponding polarization vectors for light rays in nonlinear optical materials in a nondispersive regime is here revisited and used to study wave propagation in a certain class of second-order magnetoelectric media. In particular, the 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. Estimates of the effect are presented. Some optical properties of nonlinear materials presenting a natural optic axis are also discussed.