Dynamic Terahertz Beam Steering Based on Graphene Metasurfaces

TL;DR

This paper presents a graphene-based metasurface capable of dynamic 2π phase modulation for terahertz wavefront control, enabling large-angle beam steering across a broad frequency range with high efficiency.

Contribution

It introduces a novel graphene metasurface design that achieves full phase modulation and efficient THz beam steering over a wide frequency spectrum.

Findings

Achieves a minimum reflection efficiency of 56%.

Demonstrates beam steering of up to 120 degrees in the 1.2-1.9 THz range.

Enables dynamic control of THz waves via voltage-tuned graphene resonators.

Abstract

A full (2$\pi$) phase modulation is critical for efficient wavefront manipulation. In this article, a metasurface based on graphene long/short-strip resonators is used to implement a dynamic 2$\pi$ phase modulation by applying different voltages to different graphene resonators. The configuration is found to have high reflection efficiency (minimum 56%) and has a full phase modulation in a wide frequency range. Terahertz (THz) beam steering as large as 120 degrees ($\pm60^\circ$) is demonstrated in a broad frequency range (1.2 to 1.9 THz) by changing the Fermi levels of different graphene resonators accordingly. This metasurface can provide a new platform for effectively manipulating THz waves.