Switchable Fano Resonance Filter with Graphene-based Double Freestanding Dielectric Gratings

Abstract

Fano resonance is based on plasmonic metasurfaces and has many applications in all kinds of fields. In this paper, we propose an independently switchable double-layer raster structure based on graphene. Depending on the highly adjustable nature of graphene, the Fermi energy level can be adjusted to control the Fano resonance at different wavelengths. The equivalent resonator coupling mode method is used to simulate the Fano resonance, and the transmission spectrum fits well. Functional switch at different wavelengths can be achieved using Fano resonance technology. The simulation obtained a fantastic group refractive index of the designed structure, indicating that there is a possibility to apply it in slow light. The effect of the environmental refractive index on sensing performance was studied and we found the structure has great potential in making high-sensitivity sensors. To sum up, it is hoped that this structure can make a great contribution to the manufacture of integrated optics.