Fig. 1. Structural diagram and transmission spectra. (a) T-shaped cavity coupled MIM waveguide structure; (b) transmission spectra; (c) FOM versus wavelength

Fig. 2. HZ field distributions of transmission peaks and troughs for Fano resonance. (a) First transmission dip; (b) first transmission peak; (c) second transmission trough

Fig. 3. Influences of structural parameters of T-shaped cavity. (a) Transmission spectra at different cavity heights; (b) Transmission spectra at different cavity widths; (c) relationship between cavity height and resonance peak; (d) relationship between cavity width and resonance peak

Fig. 4. Influence of refractive index on sensing characteristics. (a) Transmission spectra at different refractive indexes; (b) resonance peak wavelength versus refractive index

Fig. 5. Influences of parameters on sensing characteristics. (a) Influence of coupling distance g on Fano resonance peak; (b) FOM versus coupling distance g; (c) influence of parameter L1 on Fano resonance peak; (d) FOM versus parameter L1