Theoretical Investigation of a Simple Design of Triple-Band Terahertz Metamaterial Absorber for High-Q Sensing

Tao Chen,Runyu Zhao,Ben-Xin Wang

doi:10.3390/app9071410

Tao Chen, Runyu Zhao + Show 1 more

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https://doi.org/10.3390/app9071410

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Abstract

This paper presents a simple metamaterial design to achieve the triple-band near-perfect absorption response that can be used in the area of sensor application. The introduced absorber consists of an array of Au strip and a bulk flat Au film separated by an insulator dielectric layer. Three narrow-band resonance absorption peaks are obtained by superposing three different modes (a fundamental mode resonance and two high-order responses) of the Au strip. These resonance modes (in particular of the last two modes) have large sensitivity to the changes of the surrounding index, overlayer thickness and the refractive index of the overlayer.

Highlights

Metamaterial perfect absorbers [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22] as an important and special branch of the metamaterials have received extensive attention because of their excellent and controllable resonance characteristics that frequently used in the application fields of selective thermal emitters, materials detection, sensing, imaging, and so on
In addition to the perfect absorption of incident electromagnetic waves, there are many technologies to achieve the regulation of electromagnetic waves, such as nano-particles [23], near-zero-index materials [24], metasurfaces [25], graphene [26], metamaterials [27]
The absorbances of the three peaks and narrow-band peaks are obtained in this metamaterial structure

Summary

Introduction

Metamaterial perfect absorbers [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22] as an important and special branch of the metamaterials have received extensive attention because of their excellent and controllable resonance characteristics that frequently used in the application fields of selective thermal emitters, materials detection, sensing, imaging, and so on. The first metamaterial perfect absorber composed of three function layers (electric ring resonator-insulation dielectric layer-metal strip) was demonstrated at the microwave regime in the year of 2008 [1]. In this three-layer resonance structure, the bottom metal strip can effectively block the transmission of the incident waves, and the proper thickness of dielectric spacer layer can make the impedance of the metamaterial structure matched to that of the air. In addition to the perfect absorption of incident electromagnetic waves, there are many technologies to achieve the regulation of electromagnetic waves, such as nano-particles [23], near-zero-index materials [24], metasurfaces [25], graphene [26], metamaterials [27]. Not to mention that these technologies can regulate the absorption resonance performance of the suggested devices

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Conclusion