Fig. 1. α-Si nanoantennas hybrid phase generalized perfect vortex metasurface

Fig. 2. Schematic diagram of the rectangular α-Si nanoantenna structure and FDTD simulation results under fixed height and lattice constant. (a) Nanoantenna structure; transmission coefficient distributions of rectangular α-Si nanoantenna under (b) x-linear polarized and (c) y-linear polarized incidences; transmission phase distributions of rectangular α-Si nanoantenna under (d) x-linear polarized and (e) y-linear polarized incidence; complex transmission coefficient distributions of rectangular α-Si nanoantenna under (f) x-linear polarized and (g) y-linear polarized incidences

Fig. 3. SEM image of the fabricated α-Si nanoantenna vortex phase metasurface

Fig. 4. Experimental optical path for testing multiple concentric G-PVBs

Fig. 5. Experimental and simulated intensity patterns and interference patterns of multiple concentric G-PVBs generated by the fabricated α-Si nanoantenna hybrid phase metasurface in RCP and LCP channels. Experimental and simulated results of multiple concentric G-PVBs patterns at the focal plane in (a) LCP and (b) RCP channels; interference patterns of (c) LCP and (d) RCP channels; phase simulation diagrams of the multiple concentric G-PVBs for (e) LCP and (f) RCP channels; (g) mode purity of the G-PVBs in the experiment