Fig. 1. Schematic diagrams of the structures of an all-dielectric metasurface. (a) Schematic diagram of asymmetric nanocylindrical holes array; (b) cell structure diagram of the metasurface; (c) top view of the cell structure

Fig. 2. Metasurface transmission spectra analysis. (a) Transmission spectra of metasurfaces under different asymmetric parameters; (b) Fano fitting of transmission spectra at Δ=30 nm; (c) Q as a function of Δ

Fig. 3. Normalized field distribution at resonant wavelength with Δ=30 nm. (a) Electric field distribution in the xoy plane; (b) magnetic field distribution in the xoz plane; (c) magnetic field distribution in the yoz plane

Fig. 4. Far-field scattering contributions of electric dipole P, magnetic dipole M, toroidal dipole T, electric quadrupole Qe, and magnetic quadrupole Qm

Fig. 5. Influence of structural parameters on transmission spectra. (a) Period P; (b) cylinder height H; (c) cylinder hole radius r; (d) cylinder radius R

Fig. 6. Analysis of sensing performances. (a) Variation of transmission spectra for different analyte refractive indices; (b) wavelength shift for different analyte refractive indices