Coherent detector for the non-separability measurement of vectorial structured light

作者：Yize Liang, Shuai Cao, Lixian Liu, Fei Liu, Xukun Yin, Pei Lv, Yiming Zhang, Yunrui Zou, Liang Fang, Shuang Zheng, Zhenyu Wan, Teli Xi, Xiaopeng Shao, Jian Wang · 发表于：Light Science & Applications · 年份：2025 · DOI：10.1038/s41377-025-02035-1 · 被引用次数：11 · 研究领域：Orbital Angular Momentum in Optics、Optical Wireless Communication Technologies、Digital Holography and Microscopy

Atmospheric turbulence distorts the complex wavefront of light in free-space optical communication systems, leading to bit errors and even communication interruptions. Recently, it is found that the non-separability of vectorial structured light remains invariant when transmitting through atmospheric turbulence. This discovery offers a potential solution for turbulence-resilient communications-encoding based on the non-separability of vectorial structured light. To achieve such turbulence-resilient communications, efficient detection of the non-separability of vectorial structured light is essential, which acts as the receivers of such communication systems. So far, traditional non-separability detection schemes usually rely on bulky SLMs or DMDs, facing inherent trade-offs between single-shot capability and system compactness. In addition, the detection of mode-resolved non-separability contributions of vectorial superposition states has not yet been accomplished. Here, we propose and experimentally demonstrate a coherent detector to characterize the non-separability of vectorial structured light based on off-axis digital holography, which overcomes the limitations of traditional approaches by digitally decomposing spatial modes. Our approach may pave the way for turbulence-resilient optical communications based on non-separability coding methods and bring new insights into non-separability measurement.