Improved Fourier Analysis of Periodically Patterned Graphene Sheets Embedded in Multilayered Structures and Its Application to the Design of a Broadband Tunable Wide-Angle Polarizer

Abstract

Numerical modeling of periodically patterned graphene sheets (PPGS) embedded in planar multilayered media using Fourier-based methods suffers from very slow convergence because of the fact that the conductivity is zero in unfilled areas of the patterned surface and, thus, the so-called Li’s inverse rule is not applicable. In this paper, a simple and efficient approach is proposed to overcome this problem such that the exact boundary condition can be applied and the surface current density on PPGS can be obtained accurately. Here, the PPGS is modeled as a conductive surface and only its conductivity representation by the Fourier series is modified. The proposed method can be used easily for 1-D and 2-D periodic structures without the need to change the basic formulations of Fourier-based methods. Fast convergence and accuracy of the method will be demonstrated by computing the absorption of 1-D and 2-D PPGS. Moreover, the proposed method is utilized to design a wideband tunable wide-angle polarizer consisting of two-parallel PPGS separated by a 0.5- $\mu \text{m}$ layer of SiO2. The transmittance of the structure exceeds 95% from microwaves up to 2 THz.