Influence of the external field on photorefractive surface waves

Influence of the external field on photorefractive surface waves is studied theoretically and numerically. We demonstrate that photorefractive surface waves cannot be formed without the diffusion nonlinearity. An externally applied electric field can change the profiles of the photorefractive surface waves, especially the spatial frequency etc., and even destructs photorefractive surface waves upon a threshold value. This provides a possible method to control the formation and the shape of photorefractive surface wave. The influence of dark intensity is also discussed.