Tunable absorption enhancement in periodic elliptical hollow graphene arrays

In this contribution, a tunable plasmonic absorber consisting of periodical elliptical hollow graphene arrays deposited on SiO2 substrate is proposed in the far infrared and terahertz (THz). The simulation calculation results show that the structure supports a variety of effective tuning methods, such as changing the period, geometry parameters, Fermi level, relaxation time, incident angle, to achieve active and passive tuning. When the incident angle is set to 60°, the maximum absorption value (0.31) in our work can be achieved. Meanwhile, the red shift caused by period variations and blue shift phenomenon made of geometry parameters provides an exercisable way to select the resonance range. Therefore, these outcomes undoubtedlyoffer a unique source of inspiration for the diversity of graphene array shapes and the design and fabrication of absorption-related devices, such as filters, spatial light modulators, and sensors.