Waveguide and Plasmonic Absorption-Induced Transparency.

Abstract

Absorption-induced transparency (AIT) is one of the family of induced transparencies that has emerged in recent decades in the fields of plasmonics and metamaterials. It is a seemingly paradoxical phenomenon in which transmission through nanoholes in gold and silver is dramatically enhanced at wavelengths where a physisorbed dye layer absorbs strongly. The origin of AIT remains controversial, with both experimental and theoretical work pointing to either surface (plasmonic) or in-hole (waveguide) mechanisms. Here, we resolve this controversy by carefully filling nanoholes in a silver film with dielectric material before depositing dye on the surface. Our experiments and modeling show that not only do plasmonic and waveguide contributions to AIT both exist, but they are spectrally identical, operating in concert when the dye is both in the holes and on the surface.