Fabry-Pérot interferometer with disorder: Light localization and correlations

We study theoretically the multiple-scattering effects in an optical Fabry-P\'erot interferometer containing random elastic scatterers (and its electronic equivalent of a disordered double-barrier resonant-tunneling device). We find that coherent multiple scattering plays a crucial role in determining the transmission behavior in such a geometry. Apart from broadened resonant peaks which depend separately on the incoming- and outgoing-wave directions, we find an enhanced narrow transmission peak due to weak localization in the mirror direction, whose height is exactly a factor of 2. We also find interesting correlation effects between the incomingan intensity to the motion of a single impurity, characteristic of multiple scattering in two dimensions.