Effective optical anisotropy in evanescent wave propagation in atomic vapor

Abstract

We have observed changes in the polarization of an evanescent wave propagating in a resonant atomic vapor. The effect can be interpreted as an effective dichroism and birefringence of the vapor, the phenomenon characteristic of anisotropic media. In this case it arises from the Goos-Hänchen shift, which is different for light polarized parallel and perpendicular to the incident plane. We have also observed Faraday rotation of the evanescent wave.