High Q Factor and Sensitivity Fano Resonance Based on a Graphene-With Ring-Column Dimer Array Structure

Metasurfaces in all-dielectric are diffusely used in non-linear optical and high sensitivity biochemical sensing because of their high Q factor and sensitivity S. In this paper, a Fano interference with high Q factor is designed based on a ring-column dimer array structure, where a layer of graphene is laid at the interface of silicon and silica. The influence of Fermi energy on resonance point is studied; the maximum Q factor of 892 and the FWHM = 1.65 nm are obtained respectively at the Fermi level \({E}_{f}\) $E_f$  = 0.5 eV of graphene. What is more, as a refractive index sensor, the structure can achieve a sensitivity of up to the 1520.1 nm RIU⁻¹. In addition, the proposed structure has the advantages of simple structure and easy fabrication and has potential applications in optical switches and optical filters.