Abstract

Nonlinear surface and guided waves are potential candidates for information carriers in integrated all-optic signal processors. The instability of these waves determines whether they are available for application. The understanding of the mechanisms of distributive excitation of these waves is a prerequisite for using them. For nonlinear waves which degenerate into linear waves in the limit of small amplitudes, instability is deducible using Whitham's method, if the explicit power-dependent dispersion relation can be established. We present a perturbation method which is capable of analyzing the instability even if the powerdependent dispersion relation cannot be found or the waves have no linear analogy. We applied this method to the nonlinear surface wave supported by an interface between a nonlinear metal and vacuum, where power-dependent dispersion relation cannot be found, and subsequently developed a formalism governing the distributive grating and prism excitations of this wave. The self-modulation of this wave is found to be comparable with that of waves supported by Kerr type media.

© 1989 Optical Society of America