Fig. 1. Schematic of near-infrared chiral metasurface for circular polarization detection. (a) Principle of circular polarization detection of chiral metasurface; (b) top view of the meta-atom

Fig. 2. Simulation results of circular dichroism of chiral metasurface. (a) Transmission spectra of RCP and LCP light; (b) variation in C_D and E_R with wavelength

Fig. 3. Analysis of polarization components in the transmitted field. (a) Analysis of transmitted field polarization components under LCP light incidence with RCP and LCP light as the orthogonal base; (b) analysis of transmitted field polarization components under RCP light incidence with RCP and LCP light as the orthogonal base

Fig. 4. Electric field distribution of cross-section at different heights. (a)‒(c) Electric field distribution at the substrate‒metasurface interface (z=0 nm), the middle cross-section of silicon layer (z=175 nm), and the metasurface‒air interface (z=350 nm) under LCP light incidence; (d)‒(f) electric field distribution at the substrate‒metasurface interface (z=0 nm), the middle cross-section of silicon layer (z=175 nm), and the metasurface‒air interface (z=350 nm) under RCP light incidence

Fig. 5. Variation in circular dichroism with structural geometric parameters. (a) L; (b) L1; (c) w1; (d) w11; (e) w12; (f) L2; (g) w2; (h) w21; (i) w22; (j) x1; (k) x2

Fig. 6. Impact of tip structure of meta-atoms on the circular dichroism performance of the device. (a) Schematic of the structure of meta-atoms after rounding the tip; (b) comparison of circular dichroism (C_D) of the device before and after the tip rounding; (c) comparison of extinction ratio (E_R) of the device before and after the tip rounding