Abstract

Most early studies of nonlinear optical wave propagation were concentrated on Kerr-like media. Currently there is rapidly expanding interest in media with quadratic non­linearity [1]. This is partly due to the idea of cascading of parametric processes, which enables concepts familiar in Kerr media to be transferred to quadratic media. Here we consider modulational instabilities (MI) of stripe and ring solitary waves in quadratic nonlinear media. In the case of the 1D spatial solitary stripe it can cause instability growth along the second transverse dimension, or, in the time domain, due to group velocity dispersion (GVD). Ring structures can show instability due to azimuthal modulation.

© 1998 IEEE