Multiple Fano resonances in metal–insulator–metal waveguide with umbrella resonator coupled with metal baffle for refractive index sensing |
(a) Transmission spectra of the system with different values of vertical cavity lengths H, and (b) resonance wavelengths of the Fano resonance peaks FR1, FR2, FR3, FR4, and Lorentz resonance peak LR changing with vertical cavity length. |