Tunable polarization rotation using non-chiral all-dielectric metasurfaces

In this paper, we theoretically and numerically investigate non-chiral all-dielectric metasurfaces for controlling the polarization angle of linearly polarized light at a 1550 nm telecommunication wavelength. In contrast to conventional chiral metasurfaces, where optical activity is a result of a weak response to two circularly polarized components, our polarization rotator employs two silicon antenna in a unit cell as quarter-wave plates to generate left and right circularly polarized light. The polarization orientation of the transmitted linearly polarized light is subsequently decided by the phase retardation between the two opposite circularly polarized light beams. To demonstrate the concept, we modeled a series of metasurfaces, varying the phase differences between the circularly polarized light beams, to generate linearly polarized light with polarization angles ranging from 0 degrees to 90 degrees. We believe that our findings will further expand and promote new applications of metasurfaces.