Analysis of surface plasmon excitation at terahertz frequencies with highly-doped graphene sheets via attenuated total reflection

TL;DR

This paper investigates the excitation of surface plasmons in doped graphene at terahertz frequencies, proposing methods to overcome momentum mismatch and demonstrating potential for sensing and waveguiding applications.

Contribution

It introduces a numerical analysis showing how high doping levels and multilayer graphene enable surface plasmon excitation up to 10 THz and beyond.

Findings

Surface plasmons can be excited up to 10 THz with monolayer graphene.

Higher frequencies are achievable with multilayer graphene.

Highly-confined surface modes are promising for terahertz sensing and waveguiding.

Abstract

Excitation of surface plasmons supported by doped graphene sheets at terahertz frequencies is investigated numerically. To alleviate the momentum mismatch between the highly-confined plasmon modes and the incident radiation, it is proposed to increase the surface conductivity of graphene through high doping levels or with few-layer graphene. For currently achievable doping levels, our analysis shows that surface plasmons on monolayer graphene may be excited at operating frequencies up to about 10 THz (~ 41.3 meV) with a high-index coupling prism, and higher frequencies/energies are possible for few-layer graphene. These highly-confined surface modes are promising for sensing and waveguiding applications in the terahertz regime.