PERIODIC MODELS FOR THIN OPTIMAL ABSORBERS OF ELECTROMAGNETIC-RADIATION

We study a system composed of two thin crossed lamellar gratings, with lamellae composed of a Drude metal. We show that such a system can yi eld striking behavior for wavelengths of electromagnetic radiation muc h longer than the grating period, with reflectance, transmittance, and absorptance being independent of wavelength. We thus present periodic models that can duplicate the behavior of thin critical metallic film s while having a much simpler and more practical geometry than they.