Small Perturbation Method for Scattering From Rough Multilayers

In this paper, we present an elegant closed form solution obtained applying perturbation theory to three-dimensional layered structures with an arbitrary number of rough interfaces. A general method has been developed to treat layered structures that can be described by small changes with respect to an idealized (unperturbed) structure, whose associated problem is exactly solvable. The final expression, beyond the compactness, allows us to directly prove that our formulation satisfies the reciprocity principle.