Interaction of two optical beams at a symmetric random surface

Recently it was shown that the incoherent part of light scattered from random surfaces with even profiles displays a well-defined peak in the specular direction. This effect has been termed specular enhancement.

Here we present an experimental and theoretical study of the scattering of two coherent optical beams from a symmetric random surface. It is found that, in addition to the two sharp peaks corresponding to the enhancements in the specular directions, there is a third peak that is due to the interaction of the two optical beams at the surface.