当前位置: X-MOL 学术Light Sci. Appl. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Nano-precision metrology of X-ray mirrors with laser speckle angular measurement
Light: Science & Applications ( IF 19.4 ) Pub Date : 2021-09-22 , DOI: 10.1038/s41377-021-00632-4
Hongchang Wang 1 , Simone Moriconi 1, 2 , Kawal Sawhney 1
Affiliation  

X-ray mirrors are widely used for synchrotron radiation, free-electron lasers, and astronomical telescopes. The short wavelength and grazing incidence impose strict limits on the permissible slope error. Advanced polishing techniques have already produced mirrors with slope errors below 50 nrad root mean square (rms), but existing metrology techniques struggle to measure them. Here, we describe a laser speckle angular measurement (SAM) approach to overcome such limitations. We also demonstrate that the angular precision of slope error measurements can be pushed down to 20nrad rms by utilizing an advanced sub-pixel tracking algorithm. Furthermore, SAM allows the measurement of mirrors in two dimensions with radii of curvature as low as a few hundred millimeters. Importantly, the instrument based on SAM is compact, low-cost, and easy to integrate with most other existing X-ray mirror metrology instruments, such as the long trace profiler (LTP) and nanometer optical metrology (NOM). The proposed nanometrology method represents an important milestone and potentially opens up new possibilities to develop next-generation super-polished X-ray mirrors, which will advance the development of X-ray nanoprobes, coherence preservation, and astronomical physics.



中文翻译:

具有激光散斑角测量的 X 射线镜的纳米精密计量

X 射线反射镜广泛用于同步辐射、自由电子激光器和天文望远镜。短波长和掠入射对允许的斜率误差施加了严格的限制。先进的抛光技术已经生产出斜率误差低于 50 nrad 均方根 (rms) 的反射镜,但现有的计量技术难以对其进行测量。在这里,我们描述了一种激光散斑角测量 (SAM) 方法来克服这些限制。我们还证明,通过利用先进的亚像素跟踪算法,可以将斜率误差测量的角度精度降低到 20nrad rms。此外,SAM 允许测量曲率半径低至几百毫米的二维反射镜。重要的是,基于 SAM 的仪器结构紧凑、成本低、并且易于与大多数其他现有 X 射线反射镜计量仪器集成,例如长轨迹轮廓仪 (LTP) 和纳米光学计量 (NOM)。所提出的纳米计量学方法代表了一个重要的里程碑,并有可能为开发下一代超抛光 X 射线镜开辟新的可能性,这将推动 X 射线纳米探针、相干保持和天文物理学的发展。

更新日期:2021-09-22
down
wechat
bug