Zhang Shenglan, Tian Ximin, Xu Junwei, Xu Yaning, Huang Yafeng, Xu Kun, Ma Xiaolong, Yu Zhanjun, Fu Linjie
Opt Express. 2024 Sep 23;32(20):34662-34677. doi: 10.1364/OE.533014.
Vector vortex beams, encompassing orbital angular momentum (OAM) and polarization states, have sparked considerable interest owing to their diverse potential applications. Although existing 3D optical devices are constrained to manipulating vector fields with a single function in one dimension, recent progressions have spawned compact and integrated approaches for multidimensional and multifunctional vector manipulation by leveraging metasurfaces, displacing cumbersome optical setups. Nonetheless, a notable obstacle lingers in achieving simultaneous control over the OAM and polarization states for focused vector beams using a single metasurface. Here, we introduce a versatile all-dielectric metasurface platform designed to generate vector vortex beams with customized OAM and polarization states. Employing a hybrid-phase modulation approach, we have successfully demonstrated three spin-multiplexed metasurface platforms capable of generating versatile vector vortex beams, featuring customized independent polarization states along the propagation path characterized by coplanar distinct topological charges coupled with longitudinal varying polarization states. This enables the creation of vector vortex beam arrays with coplanar-customized OAM accompanied by longitudinal varying polarization states, respectively. This platform operates by harnessing the coherent superposition of orthogonal circularly polarized components with unique topological charges while controlling their axial phase difference. Moreover, as a proof-of-concept demonstration, the third metasurface encoding customized OAM and polarization states in the parallel channels of versatile vector vortex beams are implemented for optical information encryption. Our findings not only enable the generation of complex vector fields with tailored OAM and polarization states but also open up new possibilities for advanced beam shaping, polarization switchable devices, information encryption, and versatile light-matter interactions.
矢量涡旋光束包含轨道角动量（OAM）和偏振态，因其多样的潜在应用而引发了广泛关注。尽管现有的三维光学器件局限于在一维中操纵具有单一功能的矢量场，但最近的进展催生了通过利用超表面进行多维和多功能矢量操纵的紧凑集成方法，取代了繁琐的光学装置。然而，使用单个超表面实现对聚焦矢量光束的OAM和偏振态的同时控制仍然存在一个显著障碍。在此，我们介绍一种通用的全介质超表面平台，旨在生成具有定制OAM和偏振态的矢量涡旋光束。采用混合相位调制方法，我们成功展示了三个自旋复用超表面平台，能够生成通用的矢量涡旋光束，其特点是沿传播路径具有定制的独立偏振态，由共面不同拓扑电荷与纵向变化的偏振态相结合来表征。这使得能够分别创建具有共面定制OAM且伴有纵向变化偏振态的矢量涡旋光束阵列。该平台通过利用具有独特拓扑电荷的正交圆偏振分量的相干叠加，同时控制它们的轴向相位差来运行。此外，作为概念验证演示，在通用矢量涡旋光束的并行通道中编码定制OAM和偏振态的第三个超表面被用于光学信息加密。我们的发现不仅能够生成具有定制OAM和偏振态的复杂矢量场，还为先进的光束整形、偏振可切换器件、信息加密以及通用的光与物质相互作用开辟了新的可能性。
