Kewish Cameron M, Guizar-Sicairos Manuel, Liu Chian, Qian Jun, Shi Bing, Benson Christa, Khounsary Ali M, Vila-Comamala Joan, Bunk Oliver, Fienup James R, Macrander Albert T, Assoufid Lahsen
Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
Opt Express. 2010 Oct 25;18(22):23420-7. doi: 10.1364/OE.18.023420.
We have used coherent X-ray diffraction experiments to characterize both the 1-D and 2-D foci produced by nanofocusing Kirkpatrick-Baez (K-B) mirrors, and we find agreement. Algorithms related to ptychography were used to obtain a 3-D reconstruction of a focused hard X-ray beam waist, using data measured when the mirrors were not optimally aligned. Considerable astigmatism was evident in the reconstructed complex wavefield. Comparing the reconstructed wavefield for a single mirror with a geometrical projection of the wavefront errors expected from optical metrology data allowed us to diagnose a 40 μrad misalignment in the incident angle of the first mirror, which had occurred during the experiment. Good agreement between the reconstructed wavefront obtained from the X-ray data and off-line metrology data obtained with visible light demonstrates the usefulness of the technique as a metrology and alignment tool for nanofocusing X-ray optics.
我们利用相干X射线衍射实验对纳米聚焦柯克帕特里克-贝兹（K-B）镜产生的一维和二维焦点进行了表征，结果吻合。使用与叠层成像相关的算法，利用镜子未优化对准时测量的数据，获得了聚焦硬X射线束腰的三维重建。在重建的复波场中明显存在相当大的像散。将单个镜子的重建波场与光学计量数据预期的波前误差的几何投影进行比较，使我们能够诊断出实验过程中第一面镜子入射角出现了40微弧度的未对准。从X射线数据获得的重建波前与用可见光获得的离线计量数据之间的良好吻合，证明了该技术作为纳米聚焦X射线光学的计量和对准工具的实用性。
