Abstract

We consider a laser incident normally on a waveguide with a Kerr nonlinearity. Although the incident laser is uniform in the plane of the waveguide, the waveguide fields can be unstable to growth, forming coherent, periodic structures. This is shown to be the same process as the divergence of the reflectivity in a phase conjugate mirror produced by degenerate four- wave mixing. We find that the initial field structures grow exponentially with time until interactions nonlinear in the waveguide fields became important. By including these interactions we examine saturation of the instability and present a steady state solution.

© 1989 Optical Society of America