Broadband terahertz metamaterial absorber based on sectional asymmetric structures.

Cheng Gong,Jing Yang,Weiwei Liu,Mingzhou Zhan,Yuejin Zhao,Zhigang Wang,Haitao Liu

doi:10.1038/srep32466

Abstract

We suggest and demonstrate the concept and design of sectional asymmetric structures which can manipulate the metamaterial absorber’s working bandwidth with maintaining the other inherent advantages. As an example, a broadband terahertz perfect absorber is designed to confirm its effectiveness. The absorber’s each cell integrates four sectional asymmetric rings, and the entire structure composed of Au and Si3N4 is only 1.9 μm thick. The simulation results show the bandwidth with absorptivity being larger than 90% is extended by about 2.8 times comparing with the conventional square ring absorber. The composable small cell, ultra-thin, and broadband absorption with polarization and incident angle insensitivity will make the absorber suitable for the applications of focal plane array terahertz imaging.

Highlights

We suggest and demonstrate the concept and design of sectional asymmetric structures which can manipulate the metamaterial absorber’s working bandwidth with maintaining the other inherent advantages
The bimaterial cantilever focal plane array (FPA) imaging sensor integrated with metamaterial absorber has gained increased attention owing to its many distinctive properties[2,3,4,5]
In 2012, Alves et al reported a micro-electro-mechanical systems (MEMS) bimaterial THz sensor operating at 3.8 THz

Summary

Introduction

We suggest and demonstrate the concept and design of sectional asymmetric structures which can manipulate the metamaterial absorber’s working bandwidth with maintaining the other inherent advantages. The composable small cell, ultra-thin, and broadband absorption with polarization and incident angle insensitivity will make the absorber suitable for the applications of focal plane array terahertz imaging. In 2011, Tao et al from Boston University proposed a metamaterial absorbing enhanced optical-readout bimaterial cantilever pixels for Microwave and Terahertz (THz) wave imaging[1]. The bimaterial cantilever focal plane array (FPA) imaging sensor integrated with metamaterial absorber has gained increased attention owing to its many distinctive properties[2,3,4,5]. In 2015, Ma et al demonstrated an infrared bimaterial cantilever focal plane array integrated with metamaterial absorber to enhance the infrared imaging performance[6]. In the following a broadband THz absorber based on the structures will be demonstrate to www.nature.com/scientificreports/

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Conclusion