Abstract

Recently¹, an exact theory of the irradiated nonlinear Fabry-Perot cavity and the ensuing multistability has been published. In this paper this approach is developed further and an exact treatment for the reflectivity and transmissivity of an optically isotropic structure of dielectric layers characterised by a third-order polarisation tensor at arbitrary angles of incidence is presented. The calculations use exact² solutions of the nonlinear wave equation, rather than the commonly used ray treatment. This takes into account fully the standing wave effect and permits a precise examination of the interaction between the forward and backward travelling waves and the relationship between the transmissivity resonance condition and changes in the field profile. For an s-polarised incident wave an analytical solution is found for arbitrary angles of incidence and layer thicknesses. It is discovered that for certain ranges of layer thickness the system displays a multivalued response only above a critical angle. This bistability is achieved for irradiances much lower than those reported previously¹ for normal incidence and indicates possible applications for optical processing. This plane wave treatment is supplemented by a numerical beam simulation which goes beyond the usual Fresnel approximation by utilising novel boundary conditions which permit the demostration of bistability.

© 1988 Optical Society of America