Fano Resonance Based on Metal-Insulator-Metal Waveguide-Coupled Double Rectangular Cavities for Plasmonic Nanosensors

• Published in: Sensors (Basel, Switzerland) Vol. 16; no. 5; p. 642
• Main Authors: Zhang, Zhidong, Luo, Liang, Xue, Chenyang, Zhang, Wendong, Yan, Shubin
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 05.05.2016; MDPI
• Subjects: Asymmetry; Design; Fano resonance; Finite element method; Holes; Mathematical models; metal-insulator-metal waveguide; Plasmonics; Propagation; Refractive index; refractive index sensor; Refractivity; Sensors; surface plasmon polaritons; China; Fano resonance; finite element method; surface plasmon polaritons; metal-insulator-metal waveguide; refractive index sensor
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s16050642

A refractive index sensor based on metal-insulator-metal (MIM) waveguides coupled double rectangular cavities is proposed and investigated numerically using the finite element method (FEM). The transmission properties and refractive index sensitivity of various configurations of the sensor are systematically investigated. An asymmetric Fano resonance lineshape is observed in the transmission spectra of the sensor, which is induced by the interference between a broad resonance mode in one rectangular and a narrow one in the other. The effect of various structural parameters on the Fano resonance and the refractive index sensitivity of the system based on Fano resonance is investigated. The proposed plasmonic refractive index sensor shows a maximum sensitivity of 596 nm/RIU.