Tunable broadband terahertz absorber based on graphene metamaterials and VO2

Abstract

A tunable broadband terahertz (THz) absorber is designed in this paper, which is composed of graphene, silica medium and phase change material Vanadium dioxide (VO 2 ). By simultaneously changing the fermi level of graphene and conductivity of VO 2 , the dual-controlled absorber can be realized. The results show that the full width at half maximum of the absorption spectrum is 1.03 THz, the bandwidth with the absorptance above 90% is 0.65 THz, and the absorptance is close to 100% at 1.2 THz. Moreover, the absorptance, transmittance and reflectance of the absorber can be dynamically adjusted from 0 to 99%, 0–65%, and 0–74%, respectively. The large tunability allows the proposed absorber to be used as THz tunable filters, sensors, switches and modulators. • A broadband metamaterial absorber has been proposed based on the patterned graphene resonators. • Dual control and tunability is realized based on graphene array and phase change material vanadium dioxide. • The proposed structure can be dynamically tuned to act as an absorber or reflector. • The structure can be made to work in transmission or absorption mode by changing the conductivity of vanadium dioxide.