近日，华中科技大学刘世元团队实现了突破相干衍射成像的分辨率极限。相关论文于2025年8月28日发表在《光：科学与应用》杂志上。

相干衍射成像（CDI）以其无透镜的几何结构和理论上完善的传递函数，被认为是实现阿贝分辨率极限的最有前途的方法之一。然而，近年来在突破高数值孔径（NA） CDI的分辨率限制方面的研究进展仍颇具挑战性。

研究组报道了一个接近0.9NA的CDI，具有优化的成像因子（k = 0.501），首次在超高NA场景下突破了阿贝分辨率衍射极限。利用超高NA和阿贝极限k因子，研究组证明了CDI的创纪录的0.57 λ成像分辨率。该方法建立在一种称为“严格弗劳恩霍夫衍射”的新型计算框架上，该框架消除了CDI中的埃瓦尔德球效应，特别是对于高NAs。该框架将高NA，分辨率有限的CDI的一般挑战从依赖近似和复杂的几何校正转变为通过严格的基于模型的计算可解决的问题。

附：英文原文

Title: Pushing the resolution limit of coherent diffractive imaging

Author: Liu, Li, Du, Jinxiang, Zhuang, Bailin, Gong, Ming, Liu, Jiamin, Gu, Honggang, Liu, Shiyuan

Issue&Volume: 2025-08-28

Abstract: Coherent diffractive imaging (CDI), with its lensless geometry and theoretically perfect transfer function, is considered as one of the most promising paradigms to achieve the Abbe resolution limit. However, recent advances on pushing the resolution limit in high-numerical-aperture (NA) CDIs has thus far been challenging. Here, we report a nearly 0.9NA CDI with an optimized imaging factor (k=0.501), pushing the Abbe resolution diffraction limit for the first time in ultra-high-NA scenarios. Leveraging this the ultra-high NA and the Abbe-limit k-factor, we demonstrate a record-high imaging resolution of 0.57 λ for CDIs. Our approach builds upon a novel computational framework termed ‘rigorous Fraunhofer diffraction’ that eliminates the Ewald sphere effect in CDIs, particularly for high NAs. Our framework transforms the general challenge of high-NA, resolution-limited CDIs from relying on approximate and complicated geometric corrections to a solvable problem through rigorous model-based computation.

DOI: 10.1038/s41377-025-01963-2

Source: https://www.nature.com/articles/s41377-025-01963-2