Substrate-free THz focal plane metamaterial array with high absorption ratio

TL;DR

This paper introduces a substrate-free metamaterial array for THz imaging, achieving high absorption ratios and enabling real-time imaging with a scalable design and high resonant absorption.

Contribution

The work presents a novel substrate-free metamaterial array design that significantly improves THz absorption ratios for focal plane arrays.

Findings

Achieved 90.6% resonant absorption at 1.36 THz.

Designed a 100x100 pixel array with 150x150 μm pixels.

Validated the design with experimental and theoretical agreement.

Abstract

Microelectromechanical system (MEMS) focal plane array (FPA) with optical readout offers exciting opportunities for real-time terahertz (THz) imaging. However, conventional FPA suffers from a low THz absorption ratio, which further decreases the performance of THz imaging. Here, we present a simple and scalable approach for the realization of THz focal plane metamaterial array with a relatively high absorption ratio. The key idea is to combine the advantages of substrate-free structures with metamaterial. A 100 x100 THz FPA with a 150 x 150 {\mu}m pixel is designed, fabricated, and characterized. The dependence of the THz absorption ratio on the thickness of SiNx dielectric substrate film is investigated. The fabricated FPA exhibits a 90.6% resonant absorption at 1.36 THz, agreeing considerably with the theoretical simulation results. Our results imply that such a substrate-free THz focal plane metamaterial array enables the realization of THz imaging.