The design of a graphene-based wideband tunable metamaterial absorber in THz regime

Metamaterial absorber (MMA) has great potential application in many scientific and technical fields due to its perfect absorption characteristics. For most practical applications, the absorption bandwidth is one of the most important performance metrics. In this paper, we demonstrate a design of wideband tunable MMA based on graphene. The proposed absorber shows tunable wideband absorption at different externally applied voltage. The simulated absorption exceeds 90% from 7.6 THz to 8.5THz and the full width at half maximum is 75% (from 7.505THz to 8.705THz), which is achieved by using a single layer of multiple SRRs. Further study demonstrates that the absorption wideband can be greatly tuned by applying different externally applied voltage. The absorption band shifts to lower frequency with the increasing of externally applied voltage. This work opens up the possibility for designing intelligent terahertz active filter.