Graphene‐based tunable terahertz electromagnetically induced transparency using metamaterial structure

Abstract

A graphene‐based tunable electromagnetically induced transparency (EIT)‐like metamaterial structure operating at the terahertz regime is proposed and numerically analyzed. The unit cell of the metamaterial structure consists of a split‐ring resonator and twofolded‐line pair resonators, performing as the quasi‐dark mode and bright mode, respectively. When the incident waves vertically illuminate upon the metamaterial structure, a transmission peak can be observed. Moreover, the frequency of the transparency window can be flexibly adjusted by changing the Fermi energy level of graphene. A classical coupled two‐oscillator model is employed to theoretically analyze the physical mechanism of EIT‐like phenomenon, which is due to the near‐field coupling effect between the bright and the quasi‐dark modes. The proposed work will be a good candidate for the design of different graphene‐based tunable EIT devices at different frequency spectra with potential applications in optical sensors.