Plasmon excitation using a dielectric slab with diffusion type photorefractive nonlinearity

Abstract

We investigated numerically the TM electric field solutions of a dielectric slab formed by a photorefractive crystal with diffusion-type nonlinearity and limited by two metallic films. This study allows us the analysis of nonlinear surface optical waves as nonlinear solutions of the photorefractive crystal slab. Additionally, we analyzed the influence of these nonlinear solutions to excite surface plasmon-polariton waves at the metallic interfaces. In this case, the coupling between plasmons and nonlinear solutions it is possible because only TM electromagnetic waves are supported by a metal-dielectric planar waveguide. Here, we solved the vectorial and nonlinear wave equation using an iterative method based in self-autoconsistency. With this algorithm, the coupling between the waveguide modes and the surface plasmon-polariton waves are systematically investigated. The results obtained in this work are reproducible and contributes with new information for the design of tunable plasmonic devices based in nonlinear photorefractive crystals.