Terahertz absorber with dynamically switchable dual-broadband based on a hybrid metamaterial with vanadium dioxide and graphene

An absorber based on hybrid metamaterial with vanadium dioxide and graphene has been proposed to achieve dynamically switchable dual-broadband absorption property in the terahertz regime. Due to the phase transition of vanadium dioxide and the electrical tunable property of graphene, the dynamically switchablc dual-broadband absorption property is implemented. When the vanadium dioxide is in the metallic phase, the Fermi energy level of graphene is set as zero simultaneously, the high-frequency broadband from 2.05 THz to 4.30 THz can be achieved with the absorptance more than 90%. The tunable absorptance can be realized through thermal control on the conductivity of the vanadium dioxide. The proposed device acts as a low-frequency broadband absorber if the vanadium dioxide is in the insulating phase, for which the Fermi energy level of graphene varies from to 0.1 eV to 0.7 eV. The low-frequency broadband possesses high absorptance which is maintained above 90% from 1.10 THz to 2.30 THz. The absorption intensity can be continuously adjusted from 5.2% to 99.8% by electrically controlling the Fermi energy level of graphene. The absorption window can be further broadened by adjusting the geometrical parameters. Furthermore, the influence of incidence angle on the absorption spectra has been investigated. The proposed absorber has potential applications in the terahertz regime, such as filtering, sensing, cloaking objects, and switches. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

An absorber based on hybrid metamaterial with vanadium dioxide and graphene achieves dynamically switchable dual-broadband absorption in the terahertz regime by controlling the phase transition of vanadium dioxide and the Fermi energy level of graphene. The absorber can achieve high absorptance in high-frequency broadband and low-frequency broadband, with the absorption intensity being continuously adjustable by electrically controlling the Fermi energy level of graphene. The absorption window can be further broadened by adjusting geometrical parameters, making the absorber suitable for applications such as filtering, sensing, cloaking objects, and switches in the terahertz regime.