Independently tunable dual-broadband terahertz absorber based on two-layer graphene metamaterial

In this paper, we propose a graphene-based terahertz absorber with independently-tunable broadband absorption properties. In the range of 0.67-0.95 THz and 2.28-2.58 THz, the absorption 90% for both transverse electric (TE) and transverse magnetic (TM) polarization. The simulation results showed that the Fermi energy of graphene can be changed by controlling the gate voltage to control the absorption continuously and independently. Additional simulation results showed that the absorption of the metamaterial absorber is insensitive to the polarization state of the incident wave, and well-maintains over a wide range of incident angles. Furthermore, the physical mechanisms were revealed by the electric and magnetic field distributions. The proposed graphene metamaterial absorber can be applied in many promising fields like detectors, sensors, and communications.