Design of symmetrical wide-angle graphene-based mid-infrared broadband perfect absorber based on circuit model

Abstract A mid-infrared, polarization insensitive, broadband, and wide-angle graphene-based absorber exploiting arrays of nano-disks is proposed. The interaction between arrays of graphene disks provides broadband absorption over 90% from 21 to 40 THz. Circuit model and impedance matching concept are used to estimate the dimensions of the proposed absorber while the results are verified using Full-wave numerical techniques. A well-defined design procedure is proposed which is promising method to be expanded for the design of similar multi-layer absorbers. Compared with previously reported broadband absorbers, a broadband absorption of 63.3% with respect to the central frequency is achieved using a simple symmetrical structure suggested. Compared with Full-wave numerical techniques, the proposed approach not only dramatically decreases the simulation time, but it also immensely reduces the requirement of memory for simulations. The proposed structure is a multi-layer one, thus, it can be manufactured by chemical vapor deposition (CVD).