A Triple Band Highly Sensitive Refractive Index Sensor Using Terahertz Metamaterial Perfect Absorber

Abstract

This research introduces a novel design of a metamaterial absorber having the range in terahertz, capable of sensing changes in the refractive index of the encircling medium. The layout includes adjoining rectangular patches in the form of a plus symbol along with four circular patch resonators (CPRs) on the pinnacle of a Gallium Arsenide (GaAs) substrate. The proposed design comes up with three consecutive absorption peaks, with an absorptivity of 99.0%, 99.75%, and 98.0% at three different resonant frequencies of 2.36 THz, 2.675 THz, and 2.97 THz, respectively, and a Full Width Half Maximum (FWHM) of 0.08, 0.04, and 0.05. This structure's quality factor (Q-factor) at the three resonant frequencies is 29.5, 66.8, and 59.4 together with 6.75, 17.5, and 30 as figure of merit (FoM), respectively. The proposed design offers a sensitivity of 0.54 THz/RIU, 0.7 THz/RIU, and 1.5 THz/RIU in those three absorption bands. To support the selection of design parameters, parametric assessment was done. The designed sensor can find its applications in terahertz sensing.

A novel terahertz metamaterial absorber based on split-relief design for the application of refractive index sensing

“…An important application of terahertz metamaterial absorbers is in sensing. The absorption spectrum of the absorbers varies with the changes in the physical parameters such as, refractive index of the analyte [22], analyte depth [23], and temperature of the surrounding medium [24]. Thus, refractive index sensors, temperature sensors, hybrid sensors, etc.…”

Polarization-Insensitive, Wideband Terahertz Absorber Comprised of Fan-like Metasurface

“…To achieve wideband operation in the THz operating region, several multilayer metamaterial structures have been demonstrated that show high absorption peaks due to different structures [20][21][22][23][24][25][26][27][28][29][30]. These multilayer metamaterial-based absorbers have complex designs and a difficult fabrication process, leading them to show complications in integrating with commercial technologies and therefore ultimately increasing the cost.…”