Metallic nanolayers -- a sub-visible wonderland of optical properties

Abstract

It was predicted long ago that ultra-thin metallic films must exhibit unusual optical properties for radiation frequencies from rf to infrared domain. A film would remain highly reflective even when it is orders of magnitude thinner than a skin depth at any frequency. Only when it is a few nanometers thick (depending on material but not on the frequency), its reflectivity and transmittivity get equal, while its absorption peaks at 50%. It has been confirmed experimentally and new directions and applications were proposed. We review the EM theory of the phenomenon and recent developments in the field, and present some new results.