Design of Dual-Controlled Double-Band Absorber Based on Hybrid Gold Graphene and InSb Configuration

The electrically and thermally controlled double-band metamaterial absorber based on hybrid gold, graphene and InSb configuration is proposed in this paper. The results indicate that the absorption rate of double-band absorber can reach 95% based on the bright-bright mode coupling in the terahertz range (3.5 to 4.9 THz). The physical absorption mechanism can be analyzed theoretically by the radiating two-oscillator (RTO) model and electric field intensity distributions at the absorption peaks. Moreover, the absorption frequencies and rates of absorber can be electrically-tuned by adjusting the graphene chemical potential, and thermally controlled by varying the InSb temperature. When the chemical potential of graphene increases, the absorption rates of absorber decrease gradually, and the the absorption frequencies are almost unchanged. Moreover, if the temperature of Insb increases, the absorption frequencies and rates of absorber increase simultaneously. Finally, the impacts of parameters on the absorption performances and the possible uses of the double-band absorber as a refractive index sensor are further discussed. This work provides a theoretical basis for the designs of dual-tunable absorbers and sensors.