NUMERICAL-ANALYSIS OF NONLINEAR BISTABLE OPTICAL WAVE-GUIDES

In this letter we present numerical solutions of nonlinear optical waveguides illustrating the onset of bistability and the hysteresis nature for the symmetrical step index, asymmetrical step index, and asymmetrical diffused slab waveguides. Two different numerical techniques have been independently used—a finite element method (FEM) and a variational method (VM). Both methods produce numerically-stable solutions and agreement between them is good for both increasing and decreasing total power from below or above the threshold power. We have also compared our results with analytical solutions for these structures. The onset and the end of the physically unstable solutions coincides with the two power thresholds for the increasing and decreasing powers. © 1990 IEEE