High Q-factor multiple fano resonances based on triple dielectric strips metasurface

Abstract

An all-dielectric metasurface structure, composed of triple silicon strip arrayed on silica substrate, is proposed in this letter. Simulation results show that multiple Fano resonances arise in the transmission spectrum, performing high-quality (Q)- factor and nearly 100% modulation depth. The highest Q-factor of ~2000. In addition, the Cartesian multipole decomposition technique (CMDT) is adopted to verify the excitation mode of the Fano resonances. The sensing performances of the proposed structure are investigated as well, yielding the refractive index sensitivity (S) of ~ 350 nm/RIU and maximum figure of merit (FOM) of ~ 56.7 RIU^-1 . It is believed that the designed structure can provide some inspirations for the applications in nonlinear optics, optical modulations, lasing and biochemical sensing.