arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.04114physics.opticsmath-phmath.MP
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整体Mie散射

Global Mie Scattering

Weijin Chen, Qingdong Yang, Yuntian Chen, Wei Liu

备注：
Eight pages and four figures; Comments to welcome
发表信息：
ACS Omega 2020
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摘要：

在光学和光子学的各个分支学科中，米氏理论一直作为一种基本语言，发挥着不可或缺的作用。与米氏散射相关的传统研究主要集中在局部性质，如微分截面和角偏振分布。虽然在散射和吸收方面的总截面的空间集成功能是常规的调查，它们本质上取决于散射体和入射波的具体形态，因此没有表现出全球不变性的迹象。在这里，我们提出了全球米氏散射理论探索拓扑不变量的任意结构或偏振相干光的散射的任何障碍物的特性。结果表明，在远场，不依赖于任意几何和光学参数的散射体的分布和相互作用，不可避免地存在散射为零或圆偏振的方向。此外，对于每个这样的奇异方向，我们可以指定一个半整数指标，所有这些方向的指标和有界是$2$的全局拓扑不变量。我们提出的整体Mie理论，这是数学上的简单，但概念上的穿透，可以呈现新的观点，光散射和拓扑光子学的线性和非线性制度，并可能揭示新的光散射的各种形式的声波和物质波。

英文摘要：

In various subdisciplines of optics and photonics, Mie theory has been serving as a fundamental language and play indispensable roles widely. Conventional studies related to Mie scattering largely focus on local properties such as differential cross sections and angular polarization distributions. Though spatially integrated features of total cross sections in terms of both scattering and absorption are routine for investigations, they are intrinsically dependent on the specific morphologies of both the scattering bodies and the incident waves, consequently manifesting no sign of global invariance. Here we propose global Mie scattering theory to explore topological invariants for characterizations of scatterings by any obstacles of arbitrarily structured or polarized coherent light. It is revealed that, independent of distributions and interactions among the scattering bodies of arbitrary geometric and optical parameters, in the far field inevitably there are directions where the scatterings are either zero or circularly polarized. Furthermore, for each such singular direction we can assign a half-integer index and the index sum of all those directions are bounded to be a global topological invariant of $2$. The global Mie theory we propose, which is mathematically simple but conceptually penetrating, can render new perspectives for light scattering and topological photonics in both linear and nonlinear regimes, and would potentially shed new light on the scattering of acoustic and matter waves of various forms.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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