Surface-polariton and guided-wave excitation in thin-film Kerr media.

Abstract

We present a theory for the excitation of surface polaritons and guided waves in a dielectric film on a planar metal surface, via third-order nonlinearities in the dielectric (a Kerr medium). Excitation occurs by a four-wave interaction when three bulk electromagnetic waves are incident upon the film. The resonantly excited surface and/or guided waves may be at various sum or difference frequencies of the incident waves. One of the incident waves may be taken to be an applied static field, whose direction controls the polarization of the excited wave. The power flux parallel to the surface increases by several orders of magnitude at the resonance peaks corresponding to the excitation of the surface and guided waves.