Abstract

Traditionally nonlinear optical waveguide theory has evolved as a natural extension of linear waveguiding concepts. In this picture, low-power guided waves are supported by discontinuities or gradations in material refractive indices and the optical nonlinearity plays a rather passive role, modifying slightly the mode propagation constant. Linear coupled mode analysis, when extended to incorporate nonlinear effects, predicts a variety of novel switching effects such as nonlinear directional coupling or bistable response in feedback geometries. The theoretical observation that at higher incident power, a single interface (planar waveguide) could support novel stationary nonlinear surface (guided) waves, if at least one of the bounding dielectric media displayed a positive nonlinear optical response to the applied electromagnetic field, has led to an explosive growth of the literature on nonlinear waveguides [1]. Parallel studies have employed the beam propagation method (BPM) to study the asymptotic states of self-focused channels incident at oblique angles to a nonlinear interface [2]. More recently the BPM has been used as a computational tool to investigate stability of the above analytically computed stationary nonlinear surface (NSW) or guided (NGW) waves [3].

© 1989 Optical Society of America