Reconfigurable optoelectronic absorber based on nested nano disk-ribbon graphene Pattern in THz range
Ilghar Rezaei, Ava Salmanpour, Toktam Aghaee
Abstract
A two-layers, multi-band super absorber with the capability of being tuned is proposed in this paper. The idea behind the design is to realize periodic arrays of graphene disks via graphene ribbons with different lengths. Then circuit modeling is developed to be used alongside the impedance matching concept to achieve more than ten absorption peaks. The exploited spacer is a lossless polymer in the THz frequency range while the bottom of the device is occupied by a relatively thick golden plate. The developed circuit model description is verified by full-wave simulation. According to the simulation results, the proposed absorber shows more than ten peaks with absorption over 90%. The peak frequencies are interestingly able to be shifted via exploited single chemical potential variations. Additionally, deviations of absorber response against graphene electron relaxation time and device geometry are shown to be marginal which makes the presented meta-absorber, a reliable optical device.