Manipulating pattern periods via external bias for graphene-based THz Dual-Band absorber

Electrical control of terahertz (THz) radiation for high-performance THz imaging is the key point. The spectrum suffers from a lack of active and available materials such as graphene have a severely limited bias range leading to restricted tuning. Therefore, here we demonstrated an efficient tunable device exploiting a triple bias layer for patterned graphene ribbons. Here, the patterned graphene acts as a tunable surface impedance leads to electrically controlled impedance matching between the device and free space. So, a dual-band absorption is obtained which is appropriately robust against incident angle and capable of adjusting absorption peaks. The major contribution of the design is capability of manipulating patterns periods via gate biasing. This causes providing additional degree of freedom compared to conventional graphene patterns. According to the simulation results, the proposed device shows excellent tuning operation via gate bias voltages.