Theory of Plane Wave Reflection and Refraction by the Nonlinear Interface

Abstract

This report includes a review of published as well as recent results. In previous papers a new kind of optical bi-stability was proposed which is connected with reflection and refraction of light by a single surface on a nonlinear medium without a resonator or feedback; its first experimental observations were made recently by Smith et al. The main conditions required for its existence are very exact matching of the optical densities of both media and almost grazing incidence of light. These effects are available for positive nonlinearity as well as for negative non-linearity. In the last case, it is possible to excite a new kind of nonlinear wave (longitudinally inhomogeneous travelling waves) which could provide a phenomenon of strong nonlinear parallax of refracted rays along the interface. For more simple observation and some applications of reflection bistability, the use of an electro-optic element as an “artificial” nonlinearity can be proposed; this light-feedback method is analogous to that used in hybrid devices. Our last result is connected with a proposition for a new way to realize reflection bistability which consists of application of single-mode optical waveguides (one of which must be nonlinear) rather than using two semi-infinite media. This allows us to avoid the secondary effects of self-focusing and self-bending of bounded refracted beams of light in a nonlinear medium. At the same time it conserves all features of the main phenomenon of reflection bistability.

Work supported by the U.S. Air Force Office of Scientific Research under Grant No. AFOSR-80–0188.

Supported by the National Science Foundation.