A beam deflector with polarization independence double-sector units

The metasurface has drawn the attention for the potential applications in manipulating light and transmitting information. In this work, a symmetric metasurface is designed with a double-sector structure. The metasurface element is arrayed at the angle of 45 ° between the axis of symmetry and the horizontal direction. The metasurface is insensitive to the polarization of the incident light in vertical or horizontal direction, and the propagation phase can be tuned from 0 to $2\pi$ by controlling the central angle. The simulations show that the transmission efficiency is higher than 0.15 for the incident light with cross polarization and 656 nm wavelength. A beam deflector is constructed by eight double-sector elements with propagation phases, and shows an excellent polarization independent characteristics with incident of the X-, Y-, Left- and Right-polarized light, respectively. Furtherly, a metalens with a focal length of 10 m and a numerical aperture of 0.45 is designed based on the beam deflector and Fermat principle. This work expands the application of metasurface and provides the simulation basis for the application.