Diagrammatic analysis of nonlinear planar waveguides

Abstract
We show that universal V-b diagrams provide a powerful tool for analyzing the properties of nonlinear TE-polarized waves guided by optical planar structures. Here we focus on a waveguide consisting of an optically linear film bounded by a saturable nonlinear substrate and cladding. Relevant information on existence conditions and stability of the different allowed nonlinear guided waves is summarized in a few diagrams, and waveguiding properties can be immediately read off them. Critical, power-independent values of the various waveguide parameters for the different kinds of wave that exist have been identified, and we give the condition in parameter space that ensures stable propagation in a symmetric structure.