Liu Xin, Tu Shijie, Hu Yiwen, Peng Yifan, Han Yubing, Kuang Cuifang, Liu Xu, Hao Xiang
State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China.
Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China.
Nat Commun. 2025 Apr 11;16(1):3478. doi: 10.1038/s41467-025-58830-2.
Tightly focused optical fields are essential in nano-optics, but their applications have been limited by the challenges of accurate yet efficient characterization. In this article, we develop an in situ method for reconstructing the fully vectorial information of tightly focused fields in 3D space, while simultaneously retrieving the pupil functions. Our approach encodes these fields using phase-modulated focusing and polarization-split detection, followed by decoding through an algorithm based on least-sampling matrix-based Fourier transform and analytically derived gradient. We further employ a focus scanning strategy. When combined with our decoding algorithm, this strategy mitigates the imperfections in the detection path. This approach requires only 10 frames of 2D measurements to realize approximately 90% accuracy in tomography and pupil function retrieval within 10 s. Thus, it serves as a robust and convenient tool for the precise characterization and optimization of light at the nanoscale. We apply this technique to fully vectorial field manipulation, adaptive-optics-assisted nanoscopy, and addressing mixed-state problems.
紧密聚焦的光场在纳米光学中至关重要，但其应用受到准确而高效表征挑战的限制。在本文中，我们开发了一种原位方法，用于重建三维空间中紧密聚焦场的全矢量信息，同时检索光瞳函数。我们的方法使用相位调制聚焦和偏振分光检测对这些场进行编码，然后通过基于最少采样矩阵的傅里叶变换和解析推导梯度的算法进行解码。我们还采用了聚焦扫描策略。当与我们的解码算法相结合时，该策略可减轻检测路径中的缺陷。这种方法仅需10帧二维测量，就能在10秒内实现层析成像和光瞳函数检索约90%的准确率。因此，它是一种用于纳米级光的精确表征和优化的强大且便捷的工具。我们将此技术应用于全矢量场操纵、自适应光学辅助纳米显微镜以及解决混合态问题。
