Generalized Pancharatnam-Berry Phase in Rotationally Symmetric Meta-Atoms

作者：Xin Xie, Mingbo Pu, Jinjin Jin, Mingfeng Xu, Yinghui Guo, Xiong Li, Ping Gao, Xiaoliang Ma, Xiangang Luo · 发表于：Physical Review Letters · 年份：2021 · DOI：10.1103/physrevlett.126.183902 · 被引用次数：259 · 研究领域：Metamaterials and Metasurfaces Applications、Orbital Angular Momentum in Optics、Plasmonic and Surface Plasmon Research

Pancharatnam-Berry geometric phase has attracted enormous interest in subwavelength optics and electromagnetics during the past several decades. Traditional theory predicts that the geometric phase is equal to twice the rotation angle of anisotropic elements. Here, we show that high-order geometric phases equal to multiple times the rotation angle could be achieved by meta-atoms with highfold rotational symmetries. As a proof of concept, the broadband angular spin Hall effect of light and optical vortices is experimentally demonstrated by using plasmonic metasurfaces consisting of space-variant nanoapertures with C2, C3, and C5 rotational symmetries. The results provide a fundamentally new understanding of the geometric phase as well as light-matter interaction in nanophotonics.