Design of a tunable polarization insensitive graphene absorber operating at terahertz band

Recently graphene has attracted tremendous attention for its excellent properties Numerous novel graphene-based devices have come out, showing great potential of graphene for tunable applications at THz band In this paper, by stacking a monolayer of graphene on the top of the polymer substrate, a graphene-based tunable absorber is obtained owning to the voltage-controllable conductivity of graphene. Furthermore, the absorption spectra for different chemical potentials is discussed in detail. The resonance frequency of the absorber is blue-shift with increasing chemical potential. In addition, the proposed absorber shows a good stability with various polarizations due to the symmetry of the structure. These simulated results will provide approaches to obtain dynamically switchable absorbers with a compact dimension, and such design also has potential applications in THz detection, thermal emitters, sensors and THz stealth technology.