Design of an Active Dual-Controlled Broadband Absorber in the Terahertz Range

Abstract

In this work, a dual-controlled tunable broadband terahertz (THz) meta-absorber based on phase-change materials and checkerboard-shaped graphene arrays is theoretically investigated. Due to the rotational symmetry of the design, the absorption spectrum of this metasurface is polarizationindependent and maintains good properties over a wide range of incident angles. During the simulation, by changing the conductivity of vanadium dioxide (VO2), the dynamic adjustment of the absorption amplitude between 0.32 and 0.99 can be achieved. In addition, the peak absorption efficiency of the absorption spectra can be gradually increased from 0.38 to 0.99 by independently changing the Fermi energy of graphene in software. Furthermore, the physical absorption mechanism is explained in detail by introducing the impedance matching theory. Therefore, the designed dual-controlled meta-absorber opens up possible avenues for efficiently manipulating THz waves in a single metadevice.