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Tunable High-Sensitivity Four-Frequency Refractive Index Sensor Based on Graphene Metamaterial

Authors :
Xu Bao
Shujun Yu
Wenqiang Lu
Zhiqiang Hao
Zao Yi
Shubo Cheng
Bin Tang
Jianguo Zhang
Chaojun Tang
Yougen Yi
Source :
Sensors, Vol 24, Iss 8, p 2658 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

As graphene-related technology advances, the benefits of graphene metamaterials become more apparent. In this study, a surface-isolated exciton-based absorber is built by running relevant simulations on graphene, which can achieve more than 98% perfect absorption at multiple frequencies in the MWIR (MediumWavelength Infra-Red (MWIR) band as compared to the typical absorber. The absorber consists of three layers: the bottom layer is gold, the middle layer is dielectric, and the top layer is patterned with graphene. Tunability was achieved by electrically altering graphene’s Fermi energy, hence the position of the absorption peak. The influence of graphene’s relaxation time on the sensor is discussed. Due to the symmetry of its structure, different angles of light source incidence have little effect on the absorption rate, leading to polarization insensitivity, especially for TE waves, and this absorber has polarization insensitivity at ultra-wide-angle degrees. The sensor is characterized by its tunability, polarisation insensitivity, and high sensitivity, with a sensitivity of up to 21.60 THz/refractive index unit (RIU). This paper demonstrates the feasibility of the multi-frequency sensor and provides a theoretical basis for the realization of the multi-frequency sensor. This makes it possible to apply it to high-sensitivity sensors.

Details

Language :
English
ISSN :
14248220
Volume :
24
Issue :
8
Database :
Directory of Open Access Journals
Journal :
Sensors
Publication Type :
Academic Journal
Accession number :
edsdoj.2548cd2875af4c1aa7b43e139d90bc37
Document Type :
article
Full Text :
https://doi.org/10.3390/s24082658