Multiple Fano Resonances in Plasmonic Waveguide-Based Cavity and Detection of Pathogenic Virus

A technique is implemented for the generation of multiple Fano resonances in a plasmonic waveguide (PW)-based rectangular cavity. A rectangular cavity provides four Fano peaks, which can further be increased to nine by inserting the metallic bars in it. The trapped surface plasmon polaritons (SPPs) by metallic bars cause the generation of multiple Fano peaks over the wavelength range of 450–1300 nm. The obtained response is validated through the Fano profile (FP) and the Fano shape parameter is calculated for each resonance peak. The performance of the proposed device is numerically studied as a refractive index sensor, and a method for analyzing the detection of pathogenic viruses, such as severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2), is reported. Out of nine Fano peaks, the best values of sensing performance indices are obtained with a full-width at half-maximum (FWHM) of ${1}.{7} \text {nm}$ , a quality factor of 405, a sensitivity of 1145.71 nm/RIU, and a figure of merit (FOM) of ${393}.{25} \text {RIU}^{-{1}}$ .