Graphene optical-to-thermal converter

TL;DR

This paper demonstrates that doped graphene nanostructures can be engineered to produce highly tunable, narrow-band infrared thermal emission with over 90% efficiency, enabling new nanoscale infrared light sources.

Contribution

It introduces realistic graphene plasmonic designs capable of releasing over 90% of emission in narrow infrared lines, advancing tunable nanoscale thermal light sources.

Findings

Over 90% emission efficiency in narrow infrared lines

Tunable emission frequencies controlled by doping levels

Efficient heating achieved through optical pumping in anisotropic structures

Abstract

Infrared plasmons in doped graphene nanostructures produce large optical absorption that can be used for narrow-band thermal light emission at tunable frequencies that strongly depend on the doping charge. By virtue of Kirchhoff's law, thermal light emission is proportional to the absorption, thus resulting in narrow emission lines associated with the electrically controlled plasmons of heated graphene. Here we show that realistic designs of graphene plasmonic structures can release over 90% of the emission through individual infrared lines with 1% bandwidth. We examine anisotropic graphene structures in which efficient heating can be produced upon optical pumping tuned to a plasmonic absorption resonance situated in the blue region relative to the thermal emission. An incoherent thermal light converter is thus achieved. Our results open a radically different approach for designing tunable nanoscale infrared light sources.