A Polarization-Insensitive, Vanadium Dioxide-Based Dynamically Tunable Multiband Terahertz Metamaterial Absorber

Mohsin Raza; Xiaoman Li; Chenlu Mao; Fenghua Liu; Hongbo He; Weiping Wu

doi:10.3390/ma17081757

A Polarization-Insensitive, Vanadium Dioxide-Based Dynamically Tunable Multiband Terahertz Metamaterial Absorber

Materials (Basel). 2024 Apr 11;17(8):1757. doi: 10.3390/ma17081757.

Authors

Mohsin Raza^{1

2

3}, Xiaoman Li^{1

2

3}, Chenlu Mao^{1

2

3}, Fenghua Liu^{1

2

3}, Hongbo He^{1

2

3}, Weiping Wu^{1

2

3}

Affiliations

¹ Laboratory of Thin Film Optics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 390 Qinghe Road, Jiading District, Shanghai 201800, China.
² State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, 390 Qinghe Road, Jiading District, Shanghai 201800, China.
³ University of Chinese Academy of Sciences, Beijing 100049, China.

Abstract

A tunable multiband terahertz metamaterial absorber, based on vanadium dioxide (VO₂), is demonstrated. The absorber comprises a three-layer metal-insulator-metal (MIM) configuration with a split ring and slots of VO₂ on the uppermost layer, a middle dielectric substrate based on silicon dioxide (SiO₂), and a gold reflector on the back. The simulation results indicate that, when VO₂ is in the metallic state, the proposed metamaterial exhibits nearly perfect absorption at six distinct frequencies. The design achieves an average absorption of 98.2%. The absorptivity of the metamaterial can be dynamically tuned from 4% to 100% by varying the temperature-controlled conductivity of VO₂. The proposed metamaterial absorber exhibits the advantages of polarization insensitivity and maintains its absorption over 80% under different incident angle conditions. The underlying physical mechanism of absorption is explained through impedance matching theory, interference theory, and the distribution of electric fields. The ability to achieve multiband absorption with tunable characteristics makes the proposed absorber a promising candidate for applications in terahertz sensing, imaging, communication, and detection. The polarization insensitivity further enhances its practicality in various scenarios, allowing for versatile and reliable performance in terahertz systems.

Keywords: metasurface; perfect absorber; six-band absorption; terahertz functional device; terahertz radiation.

Grants and funding

This work was supported by the National Natural Science Foundation of China (NSFC) under Grants 61975219 and 52273242, the National Key R&D Program of China (Nos. 2021YFB2800703, 2021YFB2800701, 2021YFB2800700), the China Science and Technology Cloud (CSTCloud), the Alliance of International Science Organizations (ANSO) and the Chinese Academy of Sciences.