Fig. 1. Schematic, absorption spectra, and near-field chiral spectra of graphene with a=60 nm, a1=30 nm, a2=30 nm, b=100 nm, l=350 nm, and Ef=0.6eV. (a) Schematic of planar chiral graphene metasurfaces; (b) absorption spectra and (c) averaged optical chirality spectra of the volume enclosed by three graphene nanosheets of planar chiral graphene metasurfaces excited by CPL, and the inset in Fig. 1(b) shows surface charge distribution of graphene nanosheets corresponding to absorption peak wavelength excited by RCP; (d) schematic of planar symmetrical graphene metasurfaces; (e) absorption spectra and (f) averaged optical chirality of the volume enclosed by three graphene nanosheets of planar symmetrical graphene metasurfaces excited by CPL, and the inset in Fig. 1(e) shows surface charge distribution of graphene nanosheets corresponding to absorption peak wavelength excited by RCP

Fig. 2. Distributions of near-fields excited by RCP at the wavelength of CD peaks. (a) Electric fields; (b) magnetic fields; (c) near-field optical chirality enhancement; (d) enlarged views of near-field optical chirality enhancement in the center of a unit

Fig. 3. Influence of a1 (a2) on near-field chirality enhancement with the same a. (a) Schematic of graphene metasurfaces with different a1 (a2); (b) absorption spectra with different a1 (a2); (c) averaged near-field chirality enhancement spectra with different a1 (a2)

Fig. 4. Influence of a1 on near-field chirality enhancement with same a2. (a) Schematic of graphene metasurfaces with different a1; (b) absorption spectra with different a1; (c) averaged near-field chirality enhancement spectra with different a1

Fig. 5. Influence of a2 on near-field chirality enhancement with same a1. (a) Schematic of graphene metasurfaces with different a2; (b) absorption spectra with different a2; (c) averaged near-field chirality enhancement spectra with different a2

Fig. 6. Influence of b on near-field chirality enhancement of graphene metasurfaces. (a) Schematic of graphene metasurfaces with different b; (b) absorption spectra with different b; (c) averaged near-field chirality enhancement spectra with different b

Fig. 7. Influence of Ef on near-field chirality enhancement of graphene metasurfaces. (a) Absorption spectra with different Ef; (b) averaged near-field chirality enhancement spectra with different Ef

Fig. 8. Influence of chiral molecules with different handednesses on absorption spectra of graphene metasurfaces. (a) Absorption spectra of metasurfaces with the volume enclosed by graphene filled with 1 nm chiral analyte with different κ; (b) enlarged view of absorption spectra caused by chiral analyte with different κ