Coherence–Orbital Angular Momentum matrix of Schell-model sources
Coherence–Orbital Angular Momentum matrix of Schell-model sources
复制标题
相干性 - Schell 模型源的轨道角动量矩阵
DOI：
10.1364/ol.460911
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发表时间：
2022
期刊：
影响因子：
3.6
通讯作者：
Cai Yangjian
中科院分区：
文献类型：
--
作者：
Wang Fei;Zhao Zhaohui;Chen Yahong;Korotkova Olga;Cai Yangjian
相干轨道角动量 (COAM) 矩阵描述了固定源或场中、一对具有相同或不同拓扑电荷（例如 l 和 m）的螺旋模式以及一对径向位置处的二阶场相关性。在这封信中，我们揭示了具有圆对称光谱密度的大类 Schell 模型源的 COAM 矩阵的一般属性。我们的结果表明 COAM 矩阵的结构与相干度 (DOC) 的对称性密切相关。特别是，如果 DOC 是实值且旋转对称，则 COAM 矩阵是对角的；否则，它可能会获取非零的对角线元素。特别是，如果 DOC 的实部具有笛卡尔对称性，则 COAM 矩阵的元素具有偶/奇索引差 |l - m|包含有关 DOC 实部/虚部的信息。我们的结果的一个潜在应用是通过测量离轴 COAM 矩阵元素来提取光的 DOC（或物体透明度）的旋转角度。
The coherence-orbital angular momentum (COAM) matrix characterizes the second-order field correlations in stationary sources or fields, at a pair of spiral modes with the same or different topological charges, say l and m, and at a pair of radial positions. In this Letter, we reveal the general properties of the COAM matrix for the broad class of the Schell-model sources with circularly symmetric spectral densities. Our results imply that the structure of the COAM matrix is intimately related to the symmetries of the degree of coherence (DOC). In particular, the COAM matrix is diagonal if the DOC is real-valued and rotationally symmetric; otherwise, it may acquire non-zero off diagonal elements. In particular, if the real part of the DOC has Cartesian symmetry, the COAM matrix's elements with the even/odd index difference |l - m| contain information about the real/imaginary part of the DOC. A potential application of our results is envisioned for extracting the rotation angle of the DOC of light (or an object transparency) through measuring of the off-axis COAM matrix elements.