Mao Baiwei, Liu Yange, Chang Wenzhe, Chen Liang, Feng Mao, Guo Huiyi, He Jiangyong, Wang Zhi
Institute of Modern Optics, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, Tianjin, 300350, China.
Nanophotonics. 2022 Feb 24;11(7):1413-1426. doi: 10.1515/nanoph-2021-0814. eCollection 2022 Mar.
It is the basic characteristic of pure vortex light that there is a phase singularity at the origin. Such a singularity may be multiple degenerate, which determines the order of vortex light. Singularities splitting phenomenon means that singularities no longer concentrate at the origin but distribute around the space, usually occurring in impure vortex light. In this paper, we demonstrate the singularities splitting phenomenon and propose an analysis method, based on which one may rapidly estimate the modal components of impure vortex light. As two common singularity discrimination methods, the spiral and fork wire interference patterns are compared in distinguishing splitting singularities. The most widely used spiral interference pattern is revealed to be the worst form because of the low resolution. Instead, the fork wire interference pattern is with higher and easily adjusted resolution. 1‰ impurity is still able to be distinguished through fork wire interference patterns in the experiment.
纯涡旋光的基本特征是在原点处存在相位奇点。这样的奇点可能是多重简并的，这决定了涡旋光的阶数。奇点分裂现象是指奇点不再集中在原点而是分布在空间中，通常发生在非纯涡旋光中。在本文中，我们演示了奇点分裂现象并提出了一种分析方法，基于该方法可以快速估计非纯涡旋光的模式分量。作为两种常见的奇点判别方法，比较了螺旋和叉丝干涉图样在区分分裂奇点方面的情况。结果表明，由于分辨率低，最广泛使用的螺旋干涉图样是最差的形式。相反，叉丝干涉图样具有更高且易于调节的分辨率。在实验中，通过叉丝干涉图样仍能够区分出1‰的杂质。
