Graphene-based tunable multichannel filter with arithmetic sequence quasiperiodic structure

A tunable multichannel mid-infrared filter based on monolayer graphene is proposed and investigated. The optical transmission spectra are numerically simulated by the method of finite difference time-domain (FDTD). The numerical results denote that the filtering properties can be tuned by the chemical potentials of graphene, the depth of the air trench, the temperature, and the quasi-period number of the structure. The numerical results are discussed by deducing the effective refractive index of surface plasmon polaritons (SPPs) propagating on the multilayered structure of air/graphene/dielectric and air/graphene/air/dielectric. This work can provide a method to design tunable multichannel filter with a single layer of graphene. Due to its tunability and miniaturization, the proposed structure can be found application in high speed integrated photonic circuit.