A metamaterial absorber for the terahertz regime: Design, fabrication and characterization

TL;DR

This paper introduces a novel metamaterial absorber operating at terahertz frequencies, demonstrating high absorption efficiency and tunability, with potential applications in THz imaging systems.

Contribution

The authors design, fabricate, and experimentally validate a bilayer metamaterial absorber with independent tuning capabilities for permittivity and permeability at terahertz frequencies.

Findings

Achieved 70% absorption at 1.3 THz

Demonstrated absorption coefficient of 2000 cm$^{-1}$

Single unit cell design enables compact, narrow-band absorption

Abstract

We present a metamaterial that acts as a strongly resonant absorber at terahertz frequencies. Our design consists of a bilayer unit cell which allows for maximization of the absorption through independent tuning of the electrical permittivity and magnetic permeability. An experimental absorptivity of 70% at 1.3 terahertz is demonstrated. We utilize only a single unit cell in the propagation direction, thus achieving an absorption coefficient $\alpha$ = 2000 cm$^{-1}$. These metamaterials are promising candidates as absorbing elements for thermally based THz imaging, due to their relatively low volume, low density, and narrow band response.