Fig. 1. Schematic diagram of the polarization conversion metalens with extended focal depth

Fig. 2. Schematic diagram of the unit structure parameters of designed metasurface, as well as the transmittance and conversion efficiency of a single structure

Fig. 3. The electric field intensity distribution on thex-z plane of the metalens with extended focal length and polarization conversion and the metalens with normal focal length and polarization conversion

Fig. 4. Dual focus multiplexing metalens of extended focal length and polarization conversion

Fig. 5. The electric field intensity distribution on the focal plane of the metalens with extended focal length and controllable polarization