Performance comparison and analysis of dimers metasurface structures under different materials based on fano resonance

Abstract

The selection of material type has great influence on the characteristics of optical metasurface. In this paper, a dimer metasurface structure is proposed, and the finite difference time domain (FDTD) method is used to study the transmission characteristics of metasurface structure of different dimer materials under the same structural parameters, and Fano resonance peak appears in the transmission spectrum. The formation mechanism of each Fano resonance is analyzed based on multipole theory, and the spectral characteristics and sensing characteristics of the metasurface structure of each material type are compared and analyzed. The results show that the proposed metasurface structure has high sensing sensitivity under the materials selection of metal/dielectric materials, but the Fano resonance spectrum performance is poor due to the ohmic loss of metal materials. Under the choice of all-dielectric material, Fano resonance has nearly 100% modulation depth, high Q factor and FOM value. This study can provide a theoretical reference for the design of metasurface and the design of optical micro-nano structures based on Fano resonance.