High-Sensitivity All-Dielectric Fano Resonance Biosensor with Wavelength-Division Multiplexing

We designed a multifunctional all-dielectric high-sensitivity Fano resonance biosensor. The sensor features an asymmetric structure, comprising an elliptical ring and a rectangular frame, symmetrically aligned along the x-axis. When incident light is perpendicularly directed onto the device, triple Fano resonances are observed at 1547.94 nm, 1974.11 nm, and 2080.94 nm, with calculated Q-factors of 1003.25, 628.9, and 994.3, respectively. This configuration enables triple wavelength-division multiplexing (WDM) functionality in the near-infrared spectrum. Upon varying the background refractive index, the Fano resonances exhibit red shifts, with calculated sensitivities reaching 1395.4 nm/RIU, 1205.2 nm/RIU, and 1052.2 nm/RIU, demonstrating exceptional sensing performance. The WDM sensor possesses high sensitivity and holds potential application value in biomedical sensing, optical communications, and other related fields.