High-Efficiency Geometric Phase Metasurface with Multifold Rotationally Symmetric Resonators
Faizan Faraz, Zhenfei Li, Zhengping Zhang, Taufeeq Ur Rehman Abbasi, Xiong Wang, Ivan D. Rukhlenko, Weiren Zhu
Abstract
Metasurfaces based on the geometric phase principle have captured enormous interest owing to their ability to manipulate electromagnetic waves. Here we demonstrate for the first time a high-efficiency, high-order geometric phase with a 3-fold rotationally symmetric structure, which is different from traditional geometric phase structures whose phase shift is twice the rotation angle. Highly efficient full phase control of a circularly polarized incident wave was achieved through the rotation of the unit cells, with the phase shift being six times the rotation angle. The co-polarized reflection efficiency was shown to exceed 85% for frequencies from 11.3 to 11.8 GHz, with a peak value of 92.8% at 11.52 GHz. The designed metasurface was fabricated and experimentally tested by the generation of holographic images.