Plasmon-resonance emission tailoring of "origami" graphene-covered photonic gratings.

Abstract

Due to the negative coefficient of thermal expansion of graphene, temperature changes of graphene-coated photonic surfaces could induce resonant mode shifts in diffractive optical absorptance and emission. This study focuses on the modification of optical properties through folding, or "origami," of graphene covering a plasmonic metal channel grating. This work is especially critical to understanding tailored deep plasmon emission from geometrically-modulated conducting sheets such as graphene. Conformational changes in graphene on gratings are found to tailor cavity resonance emission and plasmonic oscillations such as magnetic polaritons (MPs) and surface plasmon polaritons (SPPs), respectively. Up to 46% reduction in radiative absorptance was observed through retarded MP. Excited SPP modes can increase narrowband absorptance of 0.5 through folding of graphene. Tailoring of optical absorptance can be used for applications such as photodetectors and thermal emitters.