Terahertz response of patterned epitaxial graphene

TL;DR

This study investigates how patterned epitaxial graphene interacts with terahertz radiation, demonstrating polarization-dependent transmission effects and potential applications in THz polarization control.

Contribution

It introduces a novel method of patterning large-area graphene to achieve polarization-sensitive THz transmission, supported by theoretical analysis.

Findings

Polarization contrast up to 20% observed

Enhanced polarization effect up to 50% with wire grid pattern

Excellent agreement between experiment and theoretical models

Abstract

We study the interaction between polarized terahertz (THz) radiation and micro-structured large-area graphene in transmission geometry. In order to efficiently couple the radiation into the two-dimensional material, a lateral periodic patterning of a closed graphene sheet by intercalation doping into stripes is chosen, yielding unequal transmittance of the radiation polarized parallel and perpendicular to the stripes. Indeed, a polarization contrast up to 20% is observed. The effect even increases up to 50% when removing graphene stripes in analogy to a wire grid polarizer. The polarization dependence is analyzed in a large frequency range from < 80 GHz to 3 THz, including the plasmon-polariton resonance. The results are in excellent agreement with theoretical calculations based on the electronic energy spectrum of graphene and the electrodynamics of the patterned structure.