Cover story: Liu Y L, Dong Z, Chen Y H, et al. Research advances of partially coherent beams with novel coherence structures: engineering and applications[J]. Opto-Electron Eng, 2022, 49(11): 220178

Structured light has rich adjustable spatial degrees of freedom, including amplitude, phase, polarization, degree of coherence, etc. The modulation of these degrees of freedom has triggered a variety of novel physical effects and has found use in constructing new structured light beams and a large range of applications. Compared to the fully coherent light, partially coherent beams (PCBs) have advantages in resisting the speckle noise and the fluctuations of atmospheric turbulence. Recently, the PCBs with nonconventional coherence structures have been found to have important potential applications in atmospheric transmission, optical encryption and imaging, robust information transmission, and high-quality beam shaping. In this review, we summarize in detail the progress of the theoretical construction and experimental generation of PCBs with novel coherence structures. Meanwhile, we outline their robust propagation properties in complex media and important applications in optical encryption, imaging, robust information transfer, and beam shaping. It is found the modulation of spatial coherence structure of PCBs provides not only an efficient way to resist the random fluctuations of complex environments, but also a new degree of freedom to enrich the application scopes of structured light. Finally, the development trend and the further applications of the nonconventional coherence structure engineering are prospected.