Yang Zhaohui, Wang Haiyun, Chen Yahong, Wang Fei, Gbur Greg, Korotkova Olga, Cai Yangjian
Opt Lett. 2022 Sep 1;47(17):4467-4470. doi: 10.1364/OL.467452.
The recently introduced coherence-orbital angular momentum (COAM) matrix of a partially coherent beam [Phys. Rev. A103, 023529 (2021)10.1103/PhysRevA.103.023529] is experimentally measured for the first time, to the best of our knowledge. The new methodology based on Young's interference experiment with a pair of ring-shaped slits with embedded spiral phases is thoroughly described. By introducing the phase shift of 0 and π / 2 between two ring slits, the real and imaginary parts of the elements of the COAM matrix are obtained by measuring the on-axis spectral density in the far field of the double-ring slit. We validate our protocol through measuring the COAM matrix of an elliptical Gaussian Schell-model (GSM) beam which reveals the existence of non-trivial correlations between modes with different topological indices. The experimental results agree reasonably well with the theoretical predictions.
据我们所知，首次对部分相干光束的最近引入的相干轨道角动量（COAM）矩阵[《物理评论A》103, 023529 (2021)10.1103/PhysRevA.103.023529]进行了实验测量。详细描述了基于杨氏干涉实验的新方法，该实验采用一对带有嵌入式螺旋相位的环形狭缝。通过在两个环形狭缝之间引入0和π / 2的相移，通过测量双环形狭缝远场中的轴上光谱密度来获得COAM矩阵元素的实部和虚部。我们通过测量椭圆高斯谢尔模型（GSM）光束的COAM矩阵来验证我们的方案，该矩阵揭示了具有不同拓扑指数模式之间存在非平凡相关性。实验结果与理论预测相当吻合。
