Abstract

There has been much recent interest in cascaded nonlinearity because it enables phenomena familiar in Kerr media to be observed in quadratic media. Cascading has mainly been considered in Type I geometry, which mimics a scalar χ⁽³⁾ Here we consider Type II cascading, which corresponds to a vector Kerr effect. This is especially interesting because it leads to pure cross-modulation of the two polarisations of the fundamental field. We predict that in the presence of diffraction this mechanism leads to strong excitation of patterns, domains, and soliton-like localised states primarily exhibited in the polarisation of the field.

© 1998 IEEE