Optical coherence is a fundamental characteristic of light that plays a significant role in understanding interference, propagation, light–matter interaction, and other fundamental aspects of classical and quantum wave fields. The study of optical coherence has led to a wide range of applications, including optical coherence tomography, ghost imaging, and free-space optical communications. In recent years, the complex spatial structure of optical coherence embedded in partially coherent light beams has garnered increasing attention due to the novel physical effects it induces, such as self-shaping, self-focusing, and self-splitting of beams in free space. Partially coherent light beams with non-classical spatial coherence structures have found use in many innovative applications, including overcoming the classical Rayleigh diffraction limit in optical imaging, reducing the side effects of atmospheric turbulence in free-space optical communications, coherence-based optical encryption, and robust optical signal transmission. In this article, we present a systematic review of the manipulation and measurement of the spatial coherence structure of optical beams, their propagation and light–matter interaction, as well as the applications of partially coherent light beams with structured optical coherence. We begin with the representation of the cross-spectral density function for a partially coherent light beam using Gori’s nonnegative definite condition and Wolf’s coherent-mode decomposition theory. We then discuss in detail two different strategies for experimentally manipulating the spatial coherence structure, one based on the generalized van Cittert–Zernike theorem and the other on the coherent-mode decomposition theory. Next, we provide an overview of recent progress in measuring the complex spatial coherence structure of partially coherent light beams using methods based on self-referencing holography, generalized Hanbury Brown and Twiss experiment, and incoherent modal decomposition. We study the novel physical properties of partially coherent light beams with non-conventional spatial coherence structures during their propagation in free space and through a highly focused system, as well as their interaction with atmospheric turbulence. We also discuss the effect of structured optical coherence in reducing the negative effects of atmospheric turbulence. Finally, we present the applications of spatial coherence structure engineering in optical imaging, optical encryption, robust information transmission through complex media, particle trapping, refractive index measurement, beam shaping, and ultrahigh precision angular velocity measurement. Optical coherence structure not only provides a new degree of freedom for light manipulation but also offers an effective tool for novel light applications.

光学相干性是光的基本特性，在理解干涉、传播、光与物质相互作用以及经典波场和量子波场的其他基本方面发挥着重要作用。光学相干的研究带来了广泛的应用，包括光学相干断层扫描、重影成像和自由空间光通信。近年来，部分相干光束中嵌入的光学相干的复杂空间结构由于其引起的新颖物理效应（例如自由空间中光束的自整形、自聚焦和自分裂）而受到越来越多的关注。具有非经典空间相干结构的部分相干光束已在许多创新应用中得到应用，包括克服光学成像中的经典瑞利衍射极限、减少自由空间光通信中大气湍流的副作用、基于相干性的光学加密、和强大的光信号传输。在本文中，我们系统地回顾了光束空间相干结构的操纵和测量、光束的传播和光与物质的相互作用，以及具有结构光学相干性的部分相干光束的应用。我们首先使用 Gori 的非负定条件和 Wolf 的相干模分解理论来表示部分相干光束的交叉谱密度函数。然后，我们详细讨论了两种不同的实验操纵空间相干结构的策略，一种基于广义 van Cittert-Zernike 定理，另一种基于相干模式分解理论。接下来，我们概述了使用基于自参考全息术、广义 Hanbury Brown 和 Twiss 实验以及非相干模态分解的方法测量部分相干光束的复杂空间相干结构的最新进展。我们研究具有非传统空间相干结构的部分相干光束在自由空间和通过高度聚焦系统传播期间的新颖物理特性，以及它们与大气湍流的相互作用。我们还讨论了结构化光学相干性在减少大气湍流负面影响方面的作用。最后，我们介绍了空间相干结构工程在光学成像、光学加密、通过复杂介质的鲁棒信息传输、粒子捕获、折射率测量、光束整形和超高精度角速度测量中的应用。光学相干结构不仅为光操纵提供了新的自由度，而且为新颖的光应用提供了有效的工具。