High-Sensitivity Sensing Based on Plasmon-Induced Transparency

High-sensitivity sensing based on plasmon-induced transparency (PIT) in a rectangular resonator has been investigated in detail. Multimode theory is introduced to explain the redshift and blueshift of the transmission spectrum by adjusting a structural parameter (w or h). In sensing applications, the sensitivity of the proposed structure is about 800 nm/RIU, and its figure of merit (FOM) is as high as 17280. In addition, the influences of structural parameters on FOM are researched in detail. The results indicate that structural parameters play important roles in optimizing the sensing performance, and the length (h) is more sensitive than the width (w) for FOM. The plasmonic configuration has the advantages of easy fabrication and compactness, which may find important applications in highly integrated optics devices, optical communication, and sensitive nanometer-scale refractive index sensors.