Design of Tunable Terahertz Metamaterial Sensor with Single- and Dual-Resonance Characteristic.

Jiahao Yang,Yu-Sheng Lin

doi:10.3390/nano11092212

Abstract

We present two types of refractive index sensors by using tunable terahertz (THz) metamaterial (TTM) based on two concentric split-ring resonators (SRRs) with different splits. By modifying the distance between SRRs and substrate, TTM shows tunable single- and dual-resonance characteristic. The maximum tuning range of resonance is 0.432 THz from 0.958 THz to 1.390 THz. To demonstrate a great flexibility of TTM in real application, TTM device is exposed on the surrounding ambient with different refractive index (n). The sensitivity of TTM can be enhanced by increasing SRR height, which is increased from 0.18 THz/RIU to 1.12 THz/RIU under the condition of n = 1.1. These results provide a strategy to improve the sensing performance of the metamaterial-based sensing device by properly arranging the geometric position of meta-atoms. The proposed TTM device can be used for tunable filters, frequency-selective detectors, and tunable high-efficiency sensors in the THz frequency range.

Highlights

Sensor with Single- and Terahertz (THz) wave has many unique advantages compared with electromagnetic waves in other frequency bands
We propose two designs of tunable THz metamaterial (TTM), which are composed of two concentric split-ring resonators (SRRs) (1-cut SRR) and two concentric electric SRR
The induced charge will be generated within the gap of SRR by the incident electromagnetic wave shining on the SRR and eventually forming an electric field

Summary

Introduction

Sensor with Single- and Terahertz (THz) wave has many unique advantages compared with electromagnetic waves in other frequency bands. In biological detection, many biomolecules and organic molecules have unique responses in the THz frequency band, and the fingerprint spectrum of biological tissues can be collected by THz spectrum information. It can realize label-free, non-destructive, and non-contact detection [1,2]. Owing to it is non-toxic and non-destructive to human tissue, THz sensor provides a promising and real-time biological device for practical pharmacological applications [3].

Methods

Results

Conclusion