Efficient coupling of light to graphene plasmons by compressing surface polaritons with tapered bulk materials

TL;DR

This paper introduces a numerical method to efficiently couple infrared photons to graphene plasmons by compressing surface polaritons on tapered bulk materials, enabling better integration in nanophotonic devices.

Contribution

It proposes a novel coupling technique using tapered slabs to compress surface polaritons, matching their wavelengths to graphene plasmons for improved energy transfer.

Findings

Achieved 25% conversion efficiency of photons to graphene plasmons.

Demonstrated wavelength compression from micrometers to 200 nm.

Validated the coupling mechanism through numerical simulations.

Abstract

Graphene plasmons promise exciting nanophotonic and optoelectronic applications. Owing to their extremely short wavelengths, however, the efficient coupling of photons to graphene plasmons - critical for the development of future devices - can be challenging. Here, we propose and numerically demonstrate coupling between infrared photons and graphene plasmons by the compression of surface polaritons on tapered bulk slabs of both polar and doped- semiconductor materials. Propagation of the surface phonon polaritons (in SiC) and surface plasmon polaritons (in n-GaAs) along the tapered slabs compresses the polariton wavelengths from several micrometers to around 200 nm, which perfectly matches the wavelengths of graphene plasmons. The proposed coupling device allows for a 25% conversion of the incident photon energy into graphene plasmons and, therefore, could become an efficient route towards graphene plasmon circuitry.