LAUSR

A plasmonic refractive index nanosensor based on Fano resonance was designed, the excellent performance of the structure was numerically achieved. The system consists of a metal–insulator-metal (MIM) waveguide with two silver baffles and a coupled split ring resonator (SRR), and the finite-difference time-domain (FDTD) method was utilized to study the transmission characteristics of the structure. The results show that the designed structure can excite the triple Fano resonance phenomenon. For a positive SRR structure, the transmission peak can be tuned vertically and horizontally by adjusting the structural parameters. Furthermore, the sensitivity of nanosensors can reach 1034 nm/RIU, and the maximum figure of merit (FOM) is 7.01 × 104. Interestingly, the improved symmetrical SRR structure demonstrated that the sensitivity is as high as 1053 nm/RIU, and the maximum FOM value was 1.82 × 105. High performance and good controllability can provide a new possibility for the design and optimization of nanosensor.