New features of the surface wave propagation along an exponentially graded-index layer and nonlinear substrate with generalized Kerr-type nonlinear response

Abstract

Abstract New surface waves travelling along the interface between the medium with a generalization of the Kerr nonlinearity and an exponentially graded-index layer are found. The Kerr nonlinearity generalization is assumed to be an abruptly change in the values of Kerr nonlinear response parameters from one to another after the wave amplitude exceeds the threshold value of electric field. The differences between the localization features of surface waves in self-focusing and defocusing media are established. It is shown that the bulk of the surface wave energy is transferred in the optical domain formed near the interface in the case of contact between a graded-index medium and a self-focusing one, which can play the role of the core of the waveguide system. The opposite effect is observed in the case of contact between a graded-index and a defocusing medium, when the main fraction of the surface wave energy is transferred along the graded-index layer, and in the optical domain it is much lower than in a nonlinear substrate.