美国国家加速器实验室Diling Zhu团队通过激光干涉技术实现多元件X射线光学系统的纳弧度精度动态运动轨迹控制。相关论文于2025年3月20日发表在《光：科学与应用》杂志上。

在过去的几十年里，新的X射线束源的发展速度超过了摩尔定律。当前和即将到来的衍射受限和完全相干的X射线束源，包括基于多弯消色差的同步加速器源和高重复率X射线自由电子激光器，对X射线光学系统的稳定性和精度提出了越来越严格的要求。在光束传输和光束调节光学系统中，亚微弧度尺度的寄生运动误差会导致从源到实验的相干性和亮度的显著损失。

为了应对这一挑战，研究组将基于干涉长度和角度传感以及实时校正的光学计量作为X射线光学运动控制系统的一部分。根据可调X射线腔的光学布局构建了一个原型X射线光学系统。在线干涉计量实现了对运动控制系统的动态反馈，以跟踪和补偿运动误差。该系统实现了亚微弧度级性能，因为多个光学元件被同步和连续地调整。首次原理验证测量证明了将光学计量作为大规模X射线光学系统（如单色器、延迟线，特别是X射线腔系统）运动控制架构的一部分的潜力和必要性，以实现下一代基于腔的X射线自由电子激光器。

附：英文原文

Title: Dynamic motion trajectory control with nanoradian accuracy for multi-element X-ray optical systems via laser interferometry

Author: Koehlenbeck, Sina M., Lee, Lance, Balcazar, Mario D., Chen, Ying, Esposito, Vincent, Hastings, Jerry, Hoffmann, Matthias C., Huang, Zhirong, Ng, May-Ling, Price, Saxon, Sato, Takahiro, Seaberg, Matthew, Sun, Yanwen, White, Adam, Zhang, Lin, Lantz, Brian, Zhu, Diling

Issue&Volume: 2025-03-20

Abstract: The past decades have witnessed the development of new X-ray beam sources with brightness growing at a rate surpassing Moore’s law. Current and upcoming diffraction limited and fully coherent X-ray beam sources, including multi-bend achromat based synchrotron sources and high repetition rate X-ray free electron lasers, puts increasingly stringent requirements on stability and accuracy of X-ray optics systems. Parasitic motion errors at sub-micro radian scale in beam transport and beam conditioning optics can lead to significant loss of coherence and brightness delivered from source to experiment. To address this challenge, we incorporated optical metrology based on interferometric length and angle sensing and real-time correction as part of the X-ray optics motion control system. A prototype X-ray optics system was constructed following the optical layout of a tunable X-ray cavity. On-line interferometric metrology enabled dynamical feedback to a motion control system to track and compensate for motion errors. The system achieved sub-microradian scale performance, as multiple optical elements are synchronously and continuously adjusted. This first proof of principle measurement demonstrated both the potential and necessity of incorporating optical metrology as part of the motion control architecture for large scale X-ray optical systems such as monochromators, delay lines, and in particular, X-ray cavity systems to enable the next generation cavity-based X-ray free electron lasers.

DOI: 10.1038/s41377-025-01774-5

Source: https://www.nature.com/articles/s41377-025-01774-5