Broadband anomalous reflective metasurface for complementary conversion of arbitrary incident polarization angles.

Abstract

The abrupt phase changes at the interface can modulate the polarization and wavefront of electromagnetic waves, which is the physical mechanism of the plasmonic metasurfaces. Conventional polarization converters are difficult to obtain pure polarized light, and most of the anomalously reflecting metasurfaces are limited by the specific angle of incident polarization. Here, we present a high-efficient polarization-independent metasurface for broadband polarization conversion and anomalous reflection when a plane wave with an arbitrary polarization angle is incident vertically. We vary the dimensions of the polarization conversion unit cells and arrange them periodically to cover the full 2π phase range of cross-polarized light in two orthogonal directions. The simulation results show that the pure anomalous cross-polarization efficiency is over 80% over a wavelength range from 1400nm to 1800nm. In particular, the metasurface can realize the complementary conversion of polarization angle for incident light at any polarization angle, and deflect it to a specific angle. Our design provides strategies for miniaturization and integration of polarization conversion devices and systems.