Simultaneous sorting of arbitrary vector structured beams with spin-multiplexed diffractive metasurfaces
Xiaoxin Li, Rui Feng, Fangkui Sun, Yanxia Zhang, Qi Jia, Donghua Tang, Bojian Shi, Hang Li, Yanyu Gao, Wenya Gao, Yongyin Cao, Weiqiang Ding
Abstract
Vector structured beams (VSBs) offer infinite eigenstates and open up new possibilities for high-capacity optical and quantum communications by the multiplexing of the states. Therefore, the sorting and measuring of VSBs are extremely important. However, the efficient manipulations of a large number of VSBs have simultaneously remained challenging up to now, especially in integrated optical systems. Here, we propose a compact spin-multiplexed diffractive metasurface capable of continuously sorting and detecting arbitrary VSBs through spatial intensity separation. By introducing a diffractive optical neural network with cascaded metasurface systems, we demonstrate arbitrary VSBs sorters that can simultaneously identify Laguerre–Gaussian modes (l=−4 to 4, p=1 to 4), Hermitian–Gaussian modes (m=1 to 4, n=1 to 3), and Bessel–Gaussian modes (l=1 to 12). Such a sorter for arbitrary VSBs could revolutionize applications in integrated and high-dimensional optical communication systems.