缺陷编码高维拓扑信息

中文摘要 AI 辅助

在偏振场中，斯托克斯斯格明子（Stokes skyrmions）是连续的矢量结构，其在实空间中编码整数值拓扑不变量，可在复杂扰动下实现鲁棒的光学信息编码。然而，当出现斯托克斯矢量无唯一极限值的奇点时，这种拓扑鲁棒性会失效，对基于斯格明子的信息操纵构成了根本性限制。在此，我们出人意料地发现，正是破坏常规鲁棒性的缺陷可成为拓扑信息的载体。我们将这类结构命名为斯托克斯缺陷斯格明子（Stokes defect skyrmions），其中奇异的斯托克斯响应构成了具有理论最小尺寸的可测量拓扑自由度。我们利用全介质超表面（all-dielectric metasurfaces）设计并实现了这类结构中的一种，该超表面结合了任意可控的特征快轴奇点与定制的延迟轮廓。所得场由高维整数值拓扑元组描述，在纳米尺度上提供理论上无界的信息容量。作为概念验证演示，我们将选定的元组分量映射为预定义的字母符号，在单一光场中实现了可控的高维信息表示。我们的研究确立了斯托克斯缺陷作为高维拓扑编码的功能单元，将缺陷的作用从失效点扩展为可工程化的光学信息载体。

英文摘要

In polarization fields, Stokes skyrmions are continuous vectorial textures that encode integer-valued topological invariants across real space, enabling robust optical information encoding under complex perturbations. This topological resilience, however, fails when singular points occur where the Stokes vector has no unique limiting value, placing a fundamental constraint on skyrmion-based information manipulation. Here, we show, paradoxically, that the very defects that destroy conventional resilience can become the carriers of topological information. We introduce the resulting structures as Stokes defect skyrmions, in which singular Stokes responses constitute measurable topological degrees of freedom with theoretically minimal size. We design and realize one class of them using all-dielectric metasurfaces that combine arbitrarily controlled distinguished fast-axis singularities with customized retardance profiles. The resulting fields are then described by high-dimensional integer-valued topological tuples, providing theoretically unbounded information capacity at the nanoscale. As a proof-of-concept demonstration, selected tuple components are mapped to represent predefined alphabetic symbols, realizing controlled high-dimensional information representation within a single optical field. Our results establish Stokes defects as functional units for higher-dimensional topological encoding, expanding the role of defects from failure points to engineerable carriers of optical information.

发表机构

• University of Oxford（牛津大学）
• Institute of Photonics Technology, Jinan University（暨南大学光子技术研究所）
• University of Southampton（南安普顿大学）
• Tsinghua Shenzhen International Graduate School, Tsinghua University（清华大学深圳国际研究生院）
• Nanhu Laser Laboratory（南湖激光实验室）

机构由 AI 辅助整理，请以论文原文为准。