Spin-decoupled metasurface for simultaneous detection of spin and orbital angular momenta via momentum transformation  

作　　者：Yinghui Guo Shicong Zhang Mingbo Pu Qiong He Jinjin Jin Mingfeng Xu Yaxin Zhang Ping Gao Xiangang Luo 

机构地区：[1]State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering,Institute of Optics and Electronics,Chinese Academy of Sciences,Chengdu 610209,China [2]School of Optoelectronics,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Light(Science & Applications)》2021年第4期636-647,共12页光（科学与应用)（英文版）

基　　金：the National Natural Science Funds of China under Grant Nos.61875253 and 61975210 and the Chinese Academy of Sciences Youth Innovation Promotion Association under Grant No.2019371.

摘　　要：With inherent orthogonality,both the spin angular momentum(SAM)and orbital angular momentum(OAM)of photons have been utilized to expand the dimensions of quantum information,optical communications,and information processing,wherein simultaneous detection of SAMs and OAMs with a single element and a single-shot measurement is highly anticipated.Here,a single azimuthal-quadratic phase metasurface-based photonic momentum transformation(PMT)is illustrated and utilized for vortex recognition.Since different vortices are converted into focusing patterns with distinct azimuthal coordinates on a transverse plane through PMT,OAMs within a large mode space can be determined through a single-shot measurement.Moreover,spin-controlled dual-functional PMTs are proposed for simultaneous SAM and OAM sorting,which is implemented by a single spin-decoupled metasurface that merges both the geometric phase and dynamic phase.Interestingly,our proposed method can detect vectorial vortices with both phase and polarization singularities,as well as superimposed vortices with a certain interval step.Experimental results obtained at several wavelengths in the visible band exhibit good agreement with the numerical modeling.With the merits of ultracompact device size,simple optical configuration,and prominent vortex recognition ability,our approach may underpin the development of integrated and high-dimensional optical and quantum systems.

关 键 词：MOMENTUM ANGULAR simultaneous 

分 类 号：O43[机械工程—光学工程]