Coherence vortex (CV) states provide a new way for optical manipulation and communication. As a promising option for increasing the data-transmission capacity, CV multiplexing warrants investigation. However, few studies have focused on discriminating and sorting CV states with different topological charges. In this work, we examine the cross-spectral density (CSD) of a CV state embedded in an incoherent light field and so-called incoherent vortex (ICV). Given a multiplexed ICV, we propose a method to recognize the constituting single ICVs therein. Our analytical results, which are derived according to the coherence theory and the paraxial propagation law and are given in analytical forms, show that the CSD can reveal the topological charge spectrum of a multiplexed incoherent Laguerre–Gaussian mode. This proposal can be used for free-space communication and remote sensing where light fields with low coherence are preferable to completely coherent beams.

中文翻译：

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辨别光的非相干涡态

相干涡（CV）状态为光学操纵和通信提供了一种新方法。作为增加数据传输容量的有前途的选择，CV多路复用技术值得研究。但是，很少有研究集中于对具有不同拓扑电荷的CV状态进行区分和分类。在这项工作中，我们研究了嵌入在非相干光场中的CV状态的跨谱密度（CSD）和所谓的非相干涡（ICV）。给定一个复用的ICV，我们提出了一种识别其中组成的单个ICV的方法。我们的分析结果是根据相干理论和近轴传播定律得出的，并且以分析形式给出，表明CSD可以揭示多路非相干Laguerre-Gaussian模式的拓扑电荷谱。