A New Class of Electrically Tunable Metamaterial Terahertz Modulators

TL;DR

This paper introduces a novel electrically-tunable terahertz metamaterial modulator using metallic FSS and capacitively-tunable electron layers, achieving high modulation depth with low attenuation.

Contribution

It presents a new design for terahertz modulators employing self-gated electron layers, independent of metallic FSS, applicable to various tunable materials.

Findings

Near 100% modulation depth achieved

Less than 15% attenuation demonstrated

Applicable to multiple tunable materials

Abstract

Switchable metamaterials offer unique solutions for efficiently manipulating electromagnetic waves, particularly for terahertz waves, which has been difficult since naturally occurring materials rarely respond to terahertz frequencies controllably. However, few terahertz modulators demonstrated to date exhibit simultaneously low attenuation and high modulation depth. In this letter we propose a new class of electrically-tunable terahertz metamaterial modulators employing metallic frequency-selective-surfaces (FSS) in conjunction with capacitively-tunable layers of electrons, promising near 100% modulation depth and < 15% attenuation. The fundamental departure in our design from the prior art is tuning enabled by self-gated electron layers that is independent from the metallic FSS. Our proposal is applicable to all possible electrically tunable elements including graphene, Si, MoS2, oxides etc, thus opening up myriad opportunities for realizing high performance switchable metamaterials over an ultra-wide terahertz frequency range.