THE SMALL-SLOPE APPROXIMATION METHOD APPLIED TO A THREE-DIMENSIONAL SLAB WITH ROUGH BOUNDARIES

In this paper we present new results on the small-slope approximation method. We consider dieren t three-dimensional structures like a randomly rough surface separating two dieren t media and a slab delimited by one or two rough surfaces. We extend the small-slope approxi- mation to the fourth order terms of the perturbative development, and give the expression of the cross-sections for the dieren t polarization states. Numerical examples are treated for the studied structures and a comparison with the small-perturbation is discussed.