回顾了光场相干与偏振联合调控的研究进展，重点介绍了具有特殊空间相干结构的二维部分相干矢量光束的表征、合成及在复杂环境中的鲁棒传输特性；结合纳米光子学的发展，将二维部分相干矢量光束推广到了三维部分相干矢量光场，给出了三维部分相干矢量光场的相干与偏振表征，分析了部分相干紧聚焦矢量光场中的三维偏振结构，包括偏振维度、三维非寻常偏振态、自旋角动量结构等。研究表明相干性在赋予了矢量结构光场新颖自由度的同时，导致了二维矢量光束的鲁棒传输特性以及紧聚焦矢量光场新型三维偏振结构。

Optical encryption strategies utilizing fully coherent light have been widely explored but often face challenges such as speckle noise and beam instabilities. In this work, we introduce a novel protocol for multi-channel optical information encoding and encryption using vectorial spatial coherence engineering of a partially coherent light beam. By characterizing the beam’s spatial coherence structure with a $$2 \times 2$$ coherence matrix, we demonstrate independent control over the three components of the coherence Stokes vector. This allows for three-channel optical information encoding and encryption, with applications in color image representation. Unlike existing methods based on fully coherent light modulations, our approach utilizes a two-point dependent coherence Stokes vector, proving resilient to random noise in experimental scenarios. Our findings provide a robust foundation for higher-dimensional optical encoding and encryption, addressing limitations associated with partially coherent light in complex environments.

Information encryption with optical technologies has become increasingly important due to remarkable multidimensional capabilities of light fields. However, the optical encryption protocols proposed to date have been primarily based on the first-order field characteristics, which are strongly affected by interference effects and make the systems become quite unstable during light–matter interaction. Here, we introduce an alternative optical encryption protocol whereby the information is encoded into the second-order spatial coherence distribution of a structured random light beam via a generalized van Cittert–Zernike theorem. We show that the proposed approach has two key advantages over its conventional counterparts. First, the complexity of measuring the spatial coherence distribution of light enhances the encryption protocol security. Second, the relative insensitivity of the second-order statistical characteristics of light to environmental noise makes the protocol robust against the environmental fluctuations, e.g, the atmospheric turbulence. We carry out experiments to demonstrate the feasibility of the coherence-based encryption method with the aid of a fractional Fourier transform. Our results open up a promising avenue for further research into optical encryption in complex environments.

涡旋光束具有螺旋波前、携带相位奇点和轨道角动量等物理特性,在粒子操控、量子信息、超分辨成像、光通信等领域具有重要的应用,并已成为学术界的研究热点。得益于相干光学理论的快速发展,将相干性作为新的自由度引入涡旋光束中,提出新型涡旋光束即部分相干涡旋光束。相较于完全相干涡旋光束,部分相干涡旋光束具有独特的物理内涵和光学特性,尤其是对其相干性和拓扑荷的联合调控会引发一系列奇特的新物理效应(如相干奇点、光束整形、偏振态转换、自修复等)。回顾了部分相干涡旋光束的基本理论及发展历程,着重对部分相干涡旋光束的理论模型、传输特性、实验产生、实验测量和应用基础研究进行了阐述。

A new specially correlated partially coherent beam named nonuniform multi-Gaussian correlated (NMGC) partially coherent beam is introduced. The correlation functions of such beam in x and y directions are different from each other, i.e., nonuniform correlation function in one direction and multi-Gaussian correlated Schell-model function in the other direction. The propagation properties of an NMGC partially coherent beam in free pace are demonstrated, and we find that the intensity distribution of such beam exhibits self-focusing and self-shifting effect in one direction and self-shaping effect in the other direction on propagation. The correlation-induced self-focusing and self-shaping effect will be useful in some applications, where the high power and shaped laser is required, such as material thermal processing and laser carving.of China under grant no. 11274005 and the project of the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions.

回顾了光场相干性的基本理论以及发展历程，介绍了激光相干度大小和相干函数的调控方法，以及激光相干性的测量方法，对激光相干性调控引发的物理效应及其基础应用作了介绍。激光相干性调控不但丰富了光场调控理论，而且推动了激光技术的发展。