近日，华南师范大学詹求强团队研究了λ/33轴向分辨率的无旁瓣确定性三维纳米显微镜。2025年4月21日出版的《光：科学与应用》杂志发表了这项成果。

确定性三维（3D）超分辨率显微镜可以在小体积内实现光物质相互作用，但通常轴向延伸明显比横向延伸更长。结合两个相对的物镜和多个激光束的isoSTED方法可以在λ/12水平上提供高轴向扩展，但代价是光学系统的复杂性和固有的旁瓣。多光子激发的高阶非线性效应将有利于实现亚衍射分辨率并抑制旁瓣。

为了实现易于使用、无旁瓣、高轴向分辨率的确定性3D纳米显微镜，研究组通过融合光子雪崩纳米颗粒的超高度非线性激发（UNEx）和基于镜像的双焦矢量场调制（4Pi），开发了一种纯物理确定性策略（UNEx-4Pi）。UNEx-4Pi概念的理论研究表明，随着光学非线性的增加，荧光斑点的主峰变得更尖锐，其大旁瓣高度得到抑制。此外，利用镜子辅助的单物镜双焦自干涉策略，证明了UNEx-4Pi系统的简单性和鲁棒性。

实验上，UNEx-4Pi实现了一个没有观察到旁瓣的极其收缩的焦斑，使用一个低功率CW光束实现了高达λ/33（26 nm）的轴向分辨率。研究组还证明了UNEx-4Pi方案对生物成像的超分辨率能力，BSC-1细胞的核膜以32nm的轴向分辨率进行了染色和成像。拟议的UNEx-4Pi方法将为在高度受限的空间中实现光物质相互作用铺平道路，从而推进确定性超分辨率传感、成像、光刻和数据存储等尖端技术。

附：英文原文

Title: Sidelobe-free deterministic 3D nanoscopy with λ/33 axial resolution

Author: Pan, Binxiong, Wang, Baoju, Ni, Yue, Zhao, Qi, Wang, Yuqi, Cai, Yuyan, Zhan, Qiuqiang

Issue&Volume: 2025-04-21

Abstract: Deterministic three-dimensional (3D) super-resolution microscopy can achieve light-matter interaction in a small volume, but usually with the axial extension distinctly more elongated than the lateral one. The isoSTED method combining two opposing objectives and multiple laser beams can offer high axial extension at λ/12 level, but at the cost of optical system complexity and inherent sidelobes. The high-order nonlinear effect by multiphoton excitation would benefit to achieve a sub-diffraction resolution as well as to suppress the sidelobes. Herein, to achieve an easy-to-use, sidelobe-free deterministic 3D nanoscopy with high axial resolution, we developed a purely physical deterministic strategy (UNEx-4Pi) by fusion of ultrahighly nonlinear excitation (UNEx) of photon avalanching nanoparticles and mirror-based bifocal vector field modulation (4Pi). The theoretical studies of UNEx-4Pi concept showed that the main peak of fluorescence spot became sharper and its large sidelobe height was suppressed with the increasing optical nonlinearity. In addition, the simplicity and robustness of UNEx-4Pi system were demonstrated utilizing a mirror-assisted single-objective bifocal self-interference strategy. Experimentally, UNEx-4Pi realized an extremely constringent focal spot without sidelobes observed, achieving an axial resolution up to λ/33 (26nm) using one low-power CW beam. We also demonstrated the super-resolution ability of the UNEx-4Pi scheme to bioimaging and nuclear envelope of BSC-1 cells were stained and imaged at an axial resolution of 32nm. The proposed UNEx-4Pi method will pave the way for achieving light-matter interaction in a highly confined space, thereby advancing cutting-edge technologies like deterministic super-resolution sensing, imaging, lithography, and data storage.

DOI: 10.1038/s41377-025-01833-x

Source: https://www.nature.com/articles/s41377-025-01833-x