Fig. 1. Schematic diagram of the metalens structure

Fig. 2. PB phase diagrams carried by different silicon nanopillar structural units under the action of rotation angles

Fig. 3. Schematic diagram of the incident and focusing on the all-dielectric metalens

Fig. 4. Normalized electric field intensity profile

Fig. 5. The numerical plot of the normalized electric field intensity distribution

Fig. 6. The focusing effect figures of the metalens are made of various metal materials

Fig. 7. Focal point change curves of metalens made of three metal materials

Fig. 8. Focusing effect of each wavelength in the visible light band

Fig. 9. Variation curve of the focal point of each wavelength in the visible light band

Fig. 10. Focusing effect of three theoretical focal length lenses

Fig. 11. The actual focus change position of three theoretical focal length lenses

Fig. 12. The effect of metalens focusing at each nanopillar height

Fig. 13. The focal positions of the metalens for each nanopillar height