Switchable and Dual-Tunable Multilayered Terahertz Absorber Based on Patterned Graphene and Vanadium Dioxide

Abstract

In this paper, a switchable and dual-tunable terahertz absorber based on patterned graphene and vanadium dioxide is proposed and analyzed. By controlling the Fermi level of graphene and the temperature of vanadium dioxide, the device’s function can be switched and its absorbing properties can be tuned. When the vanadium dioxide is in an insulator state, the device can be switched from near-total reflection (>97%) to ultra-broadband absorption (4.5–10.61 THz) as the Fermi level of graphene changes from 0 to 0.8 eV. When the vanadium dioxide is changed to a metal state, the device can act as a single-band absorber (when the Fermi level of graphene is 0 eV) and a dual-band absorber with peaks of 4.16 THz and 7.3 THz (when the Fermi level of graphene is 0.8 eV). Additionally, the absorber is polarization-insensitive and can maintain a stable high-absorption performance within a 55° incidence angle. The multilayered structure shows great potential for switchable and tunable high-performance terahertz devices.

Metamaterial Absorbers: From Tunable Surface to Structural Transformation

“…The integration of active materials to MAs design has been found to be effective in controlling EM properties of MAs (Figure 2g) operating at frequencies from gigahertzes (GHz), terahertz (THz), infrared (IR) and even to optical regimes. [ 84–89 ]…”

“…Combining with other tuning elements, such as varactors diodes [ 107 ] and VO 2 , [ 18,61,72,171 ] to form a hybrid scheme is another crucial while effective approach to further extending the tunability of the graphene‐based MAs. Wang et al.…”

“…The integration of active materials to MAs design has been found to be effective in controlling EM properties of MAs (Figure 2g) operating at frequencies from gigahertzes (GHz), terahertz (THz), infrared (IR) and even to optical regimes. [84][85][86][87][88][89] Employing active parts in the design of dielectric spacer is another option to engineer tunable/reconfigurable MAs. By changing the properties (i.e., μ r , ε r , and t) of dielectric space, the absorption performance of MAs can be tuned.…”

“…Combining with other tuning elements, such as varactors diodes [107] and VO 2 , [18,61,72,171] to form a hybrid scheme is another crucial while effective approach to further extending the tunability of the graphene-based MAs. Wang et al have built an MA based on a multilayered structure comprising graphene and VO 2 , as illustrated in Figure 6f.…”

A Review: The Functional Materials-Assisted Terahertz Metamaterial Absorbers and Polarization Converters

“…The proposed design solution combines the bulk DSMs and VO2, which not only opens up a novel method for the realization of a switchable absorber from three-band to wide-band absorption, but also for the control of the resonant frequency and absorption amplitude in terahertz region. By treating the manipulated characteristics through Fermi energy of graphene and the phase transition characteristics of VO2, some switchable multi-functional metamaterial structures can be constructed to realize different functions in a single metamaterial structure, including absorption with different characteristics [179][180][181][182][183][184][185][186], reflection and absorption [187,188], absorption and polarization conversion [189], and so on. In Figure 19a, H. L. Zhu et al designed a tunable metamaterial structure to realize the broad-band and multi-band absorption treating the combination of graphene and VO2 [179].…”