Dual-controlled tunable polarization-independent triple-band absorber using hybrid Dirac semimetal-vanadium dioxide metamaterial

In this paper, a dual-controlled tunable polarization-independent triple-band absorber using hybrid bulk Dirac semimetal (BDS) and vanadium dioxide (VO 2 ) metamaterial is proposed. The physical properties of the absorber can be theoretically analyzed by the equivalent circuit model (ECM). When the Fermi energy of BDS increases from 0.11 eV to 0.15 eV, the peak frequencies also gradually increase and blue shift occurs. In addition, When the VO 2 is in fully metallic state, the absorber exhibits three distinct absorption peaks with absorptances of 99.76%, 99.61% and 99.76%, respectively, with an average absorptance of 99.71%. As the the transition of VO 2 from fully metallic state to insulating state, the transmittance and reflectance increase and the absorptance gradually decreases. Moreover, due to the structure symmetry of the absorber, the absorptance exhibits polarization independent behavior. Finally, the modulations of absorptivity spectra by tailoring the structure dimension and the potential for the application of the absorber as a refractive index sensor, are further discussed. This study provides potential applications in the design of multi-band dual–controlled tunable sensors, filters and absorbers.