Guo Lina, Chen Yongzhu, Liu Xianlong, Zhang Minghui, Chen Yahong, Liu Lin, Cai Yangjian
J Opt Soc Am A Opt Image Sci Vis. 2020 Nov 1;37(11):1806-1813. doi: 10.1364/JOSAA.403719.
Free-space propagation and experimental generation of a partially coherent radially polarized (PCRP) vortex beam were studied recently [Opt. Express24, 13714 (2016)OPEXFF1094-408710.1364/OE.24.013714]. In this work, we explore the statistical properties of such a PCRP vortex beam propagating in a uniaxial crystal. We show that the anisotropy of the refractive index of the uniaxial crystal induces the asymmetrical distribution of the intensity, the degree and the state of polarization, as well as the degree of coherence of the beam during propagation. Further, by comparing the asymmetrical distribution of the statistical properties of the PRCP vortex beam with those of a PRCP beam without a vortex phase, we find that the asymmetrical features can be used for determining whether a PCRP beam carries the vortex phase. Further, we show that from the far-field distribution of the degree of coherence, we could quantify the topological charge and distinguish the handedness of the vortex phase. Our findings provide a novel approach for measuring the phase information of the partially coherent vortex beams.
最近研究了自由空间传播以及部分相干径向偏振（PCRP）涡旋光束的实验产生[《光学快报》24, 13714 (2016)OPEXFF1094 - 408710.1364/OE.24.013714]。在这项工作中，我们探索了这种PCRP涡旋光束在单轴晶体中传播时的统计特性。我们表明，单轴晶体折射率的各向异性会导致光束在传播过程中强度、偏振度和偏振态以及相干度的不对称分布。此外，通过将PRCP涡旋光束的统计特性的不对称分布与没有涡旋相位的PRCP光束的不对称分布进行比较，我们发现这些不对称特征可用于确定PCRP光束是否携带涡旋相位。进一步地，我们表明从相干度的远场分布中，我们可以量化拓扑电荷并区分涡旋相位的手性。我们的研究结果为测量部分相干涡旋光束的相位信息提供了一种新方法。
