Second harmonic generation of light in the Kretschmann attenuated total reflection geometry in the presence of surface roughness

Using a computer simulation approach we study the generation of second harm onic light in reflection and in transmission in the Kretschmann attenuated total reflection geometry. In this geometry a thin metal film is deposited on the planar base of a dielectric prism, through which p-polarized light i s incident on the film. The back surface of the film, which separates the f ilm from vacuum, is a one-dimensional, randomly rough surface, whose genera tors are normal to the plane of incidence of the light. The nonlinearity re sponsible for the second harmonic generation is assumed to arise at the pri sm-metal and metal-vacuum interfaces, and thus enters the problem only thro ugh the boundary conditions at these interfaces at the harmonic frequency. The source terms entering these boundary conditions are obtained from the s olutions of the corresponding scattering and transmission problems at the f undamental frequency. It is found that a peak in the angular dependence of the intensity of both the transmitted and reflected second harmonic light o ccurs in the directions normal to the mean scattering surface, in addition to an enhanced backscattering peak in the retroreflection direction. The en hanced transmission peak occurs in the non-radiative region, and therefore cannot be observed in the far field.