p-polarized nonlinear surface polaritons in materials with intensity-dependent dielectric functions

Abstract

We investigate the properties of p-polarized nonlinear surface polaritons (NLSP) propagating along the interfaces of optically nonlinear materials. We show that Maxwell’s equations for the NLSP can be solved exactly in quadratures for optically isotropic media with dielectric functions which can be an arbitrary function of the field intensity. The required boundary conditions can be imposed readily, and a form of the dispersion relation for the NLSP is obtained without the need to solve for the field profile first. The general results are then applied to a specific model in which the material has a nonlinear dielectric function proportional to the electric field intensity. Both the self-focusing and self-defocusing cases are studied, as well as different values of the linear dielectric functions inside and outside the material. The physically allowed regions in parameter space and the nonlinear surface-plasmon resonance conditions are examined. The field profile in each region is also investigated.