Abstract
A very efficient method for the calculation of the effective optical response of nanostructured composite systems allows the design of metamaterials tailored for specific optical polarization properties. We use our method to design two-dimensional periodic arrays of subwavelength dielectric inclusions within nanometric supported metallic thin films which behave as either an almost perfect linearly dichroic system, as a quarter-wave plate, as a system with a large circular dichroism, or as a circular polarizer. All of these systems may be tuned over a wide energy range.