Fig. 1. Schematic diagram and structural parameters of the chiral metasurface. (a) Schematic diagram of the unit structure; (b) Structural parameters of the top (left) and bottom (right) layers of the unit structure on the xoy plane

Fig. 2. Transmittance spectrum and CD spectra of chiral metasurface. (a) Transmittance spectrum; (b) CD spectra

Fig. 3. Normalized electric field distributions and equivalent electric dipole moments on the xoy plane at resonance frequency f = 0.760 THz (mode I) and f =0.856 THz (mode II) under LCP and RCP excitations

Fig. 4. Transmittance spectrum, CD spectrum of the bilayered chiral metasurface stretched in the xy direction at different relative stretching deformation and the relationship between different tensile degrees and the frequency of the maximum CD value. (a) Transmittance spectrum; (b) CD spectrum; (c) relationship between different tensile degrees and the frequency of the maximum CD value

Fig. 5. Transmittance spectrum and CD spectrum of the unstretched metasurface with different refractive indices and the relationship between the resonant frequency and refractive index of T₊₊. (a) Transmittance spectrum; (b) CD spectrum; (c) relationship between the resonant frequency and refractive index of T₊₊

Fig. 6. Transmittance T₊₊and the relationship between resonance frequency f of T₊₊ and the refractive index n with different refractive indices when the chiral metasurface is stretched in the xy direction until the relative stretching deformation reaches 10% and 20%. (a) Transmittance T₊₊(ε'=10%); (b) f vs. n (ε'=10%); (c) transmittance T₊₊(ε'=20%); (d) f vs. n (ε'=20%)