Fig. 1. Schematic of unit cell of metasurface

Fig. 2. Polarization conversion efficiencies of nano-pillars with three sizes

Fig. 3. Schematic of metasurface for spatial focusing

Fig. 4. Simulated results of single-wavelength focusing metasurface. (a)--(c) Normalized electric filed intensity distributions in focus region (xz plane); (d)--(f) normalized electric field intensity distributions at xy focus plane when z=5.00 μm; (g)--(i) normalized focal-spot electric field intensity distributions along x direction

Fig. 5. Schematic of metasurface integration and polarization conversion efficiency of nano-pillars. (a) Schematic of metasurface integration and structural diagram of unit cell; (b) polarization conversion efficiency of nano-pillars with three sizes but same size of substrate

Fig. 6. Simulated results of multi-wavelength and multifocal metasurface. (a) z=10.15 μm; (b) y=9.67 μm; (c) x=6.47 μm; (d) z=10.38 μm; (e) y=3.29 μm; (f) x=3.29 μm; (g) z=10.36 μm; (h) y=6.53 μm; (i) x=9.71 μm

Fig. 7. Electric field intensity distributions at focal point within xy plane (z=10 μm) of multi-wavelength polarization-multiplexed multifocal metasurface. (a)--(c) When RCP light is incident; (d)--(f) when LCP light is incident; (g)--(i) when LP light is incident