Optical and microwave properties of metal-insulator thin films: possibility of light localization

High frequency response (optical, infrared and microwave) of thin metal-dielectric inhomogeneous films is studied. We propose a new approach based on a direct solution of Maxwell's equations without having to invoke the quasi-static approximation. Our theory reproduces most of the known experimental results including the anomalous absorption near a percolation threshold. For the strong skin effect case or for superconducting-dielectric films we predict an electromagnetic wave localisation at the percolation threshold.