High Sensitivity Plasmonic Sensor Based on Fano Resonance with Inverted U-Shaped Resonator
Gongli Xiao, Yanping Xu, Hongyan Yang, Zetao Ou, Jianyun Chen, Hai-Ou Li, Xingpeng Liu, Lizhen Zeng, Jianqing Li
Abstract
Herein, we propose a tunable plasmonic sensor with Fano resonators in an inverted U-shaped resonator. By manipulating the sharp asymmetric Fano resonance peaks, a high-sensitivity refractive index sensor can be realized. Using the multimode interference coupled-mode theory and the finite element method, we numerically simulate the influences of geometrical parameters on the plasmonic sensor. Optimizing the structure parameters, we can achieve a high plasmonic sensor with the maximum sensitivity for 840 nm/RIUand figure of merit for 3.9 × 105. The research results provide a reliable theoretical basis for designing high sensitivity to the next generation plasmonic nanosensor.