A Tunable Strong Electric Field Ultra-Narrow-Band Fano Resonance Hybrid Metamaterial Sensor Based on LSPR

In this study, we propose a high-figure-of-merit (FOM) Fano resonance hybrid metamaterial sensor based on localized surface plasmon resonance (LSPR). After the cone index chip experiment based on LSPR, we innovatively used waveguide mode coupling to form Fano resonance to solve the problem of the inherent resonance peak spectral width of LSPR. We obtained structures that meet the requirements without increasing process difficulty by varying the nanoparticle/waveguide hybrid structural design parameters. The simulation results demonstrate that the ultra-narrow linewidth resolution, the FOM value, and the intensity of the “hot spot” can reach 4.1 nm, 152, and 52 times that of the incident light, respectively. Compared to the single LSPR or Fano resonance devices reported, the comprehensive performance is outstanding. The proposed design may significantly reduce the detection limit of the LSPR device and has the potential to be used in the field of molecule detection.