Tailoring the spatial structure of light field in multiple degrees of freedom is a research hotspot in recent years. The topology of light field, as one of the most fascinating structures, such as vortex knots and links associated with the phase singularities, is evoking increasing attention both in fundamental research and practical application. Here, an all‐dielectric metasurface device is proposed and experimentally demonstrated that can construct vortex knots and links in light field at the micro scale. These two distinct topological configurations can be switched by changing the incident polarization. Utilizing the digital holographic interference method, these topological configurations of vorticity lines are accurately characterized in three‐dimensions, and the topology‐preserving evolution of such ultra‐small fields is demonstrated. These two classical configurations exemplify the capability of multichannel manipulating topology by compact metadevice. The work may promote the application of structured light filed at the micro scale and even the creation of other physical fields with ultra‐small size.

中文翻译：

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通过全息全介电超表面捆绑偏振可切换的光学涡旋结和链接

在多个自由度中定制光场的空间结构是近年来的研究热点。作为最引人入胜的结构之一的光场拓扑，例如与相位奇异性相关的涡旋结和链节，在基础研究和实际应用中都引起越来越多的关注。在这里，提出了一种全介电的超表面装置，并通过实验证明了该装置可以在光场中以微尺度构造涡旋结和链节。可以通过更改入射极化来切换这两种不同的拓扑配置。利用数字全息干涉法，这些涡旋线的拓扑结构可以在三个维度上准确表征，并展示了这种超小场的拓扑保持演化。这两个经典配置通过紧凑的元设备体现了多通道操纵拓扑的功能。这项工作可能会促进微尺度结构化光的应用，甚至促进其他超小尺寸物理场的创建。