Is depolarization a signature of multiple scattering

We demonstrate that depolarization is not necessarily a signature of multiple scattering. Within a single scattering regime, we show that disordered systems can exhibit depolarization if two sources of disorder are present and have different individual polarization responses. To this end, we study a disordered system consisting of a randomly rough surface that separates vacuum from a medium with volume dielectric fluctuations. This scattering system depolarizes the incident light even within the single scattering regime and there exist directions of perfect depolarization which we characterize geometrically.