Tunable dual-band perfect metamaterial absorber based on a graphene-SiC hybrid system by multiple resonance modes

Abstract

We propose dynamically tunable dual-band perfect absorption of light in a composite structure, which consists of a graphene ribbon array coated on a dielectric layer, a silicon carbide (SiC) film and a distributed Bragg reflector (DBR). Two absorption peaks reaching 98.8% at 10.87 μm and 97.5% at 12.4 μm are observed in the hybrid structure. The dual-band absorption enhancement can be explained by two different mechanisms: one is attributed to the graphene localized surface plasmons (GLSP), and the other is originated from the excitation of Tamm plasmon polaritons (TPP) at the interface between SiC and DBR. Moreover, the high absorption peaks can be modulated by altering the geometrical parameters or dynamically controlling the chemical potential of graphene ribbons. More significantly, we numerically and theoretically investigate the hybridization between GLSP mode and TPP mode, which is characterized by the anti-crossing behaviour of the two modes. The mode splitting phenomenon is a typical Rabi splitting. In addition, we also study the coupling characteristics based on graphene surface plasmons (GSP) mode and TPP mode. This work offers a new paradigm for enhancing light-matter interaction through multiple resonance modes, and the proposed device could provide potential applications in MIR plasmonic devices, such as absorbers, detectors, and modulators, etc.