Fig. 1. Structural diagram of sensor

Fig. 2. Absorption spectrum of sensor

Fig. 3. Electric field and magnetic field distributions in z=0 plane. (a) Electric field and (c) magnetic field distributions at λ₁=1.025 μm; (b) electric field distribution at λ₂=1.083 μm; (d) magnetic field distribution at λ₃=1.057 μm

Fig. 4. Spectral characteristics under different conditions. (a) With and without graphene; (b) different graphene thicknesses

Fig. 5. Variation of resonant wavelength and bandwidth with sensing structural parameters. (a) Grating height; (b) dielectric layer thickness; (c) grating period; (d) wide-grating width

Fig. 6. Spectral characteristics under different refractive indexes to be measured. (a) Resonant spectra; (b) refractive index curves

Fig. 7. Spectral characteristics under different temperatures. (a) Resonant spectra; (b) temperature curves