Xie Xin, Pu Mingbo, Jin Jinjin, Xu Mingfeng, Guo Yinghui, Li Xiong, Gao Ping, Ma Xiaoliang, Luo Xiangang
State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering, Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China.
School of Optoelectronics, University of Chinese Academy of Sciences, Beijing 100049, China.
Phys Rev Lett. 2021 May 7;126(18):183902. doi: 10.1103/PhysRevLett.126.183902.
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.
在过去几十年中，潘查拉特纳姆-贝里几何相位在亚波长光学和电磁学领域引起了极大的关注。传统理论预测，几何相位等于各向异性元件旋转角度的两倍。在此，我们表明具有高折叠旋转对称性的超原子可以实现等于旋转角度多倍的高阶几何相位。作为概念验证，通过使用由具有C2、C3和C5旋转对称性的空间可变纳米孔径组成的等离子体超表面，对光和光学涡旋的宽带角自旋霍尔效应进行了实验验证。这些结果为纳米光子学中的几何相位以及光与物质相互作用提供了全新的基本理解。
