Fig. 1. Structural diagram of metasurface

Fig. 2. Phase distribution of metasurface corresponding to vortex beam with topological charge value l=1. (a) Phase distribution at z=H; (b) phase distribution at z=0; (c) compensated phase distribution

Fig. 3. Phase distributions of metasurfaces corresponding to vortex beams with topological charge values l=±1, l=±2, l=±3, l=±4

Fig. 4. Structural diagram of metasurface unit. (a) Geometric structure of polarization grating; (b) geometric structure of notch ring; (c) simulation model of metasurface unit

Fig. 5. Simulation results of metasurface unit. (a) Transmission phase; (b) transmission efficiency

Fig. 6. Local unit distributions of metasurface

Fig. 7. Simulation results of vortex beams with topological charge values l=1, 2, 3, 4. (a)-(d) Phase distributions; (e)-(h) amplitude distributions; (i)-(l) far field radiation patterns