Department of Electronic and Electrical Engineering, University of Sheffield, Sheffield S1 3JD, UK.
Nat Commun. 2013;4:1669. doi: 10.1038/ncomms2640.
Ptychography is a form of scanning diffractive imaging that can successfully retrieve the modulus and phase of both the sample transmission function and the illuminating probe. An experimental difficulty commonly encountered in diffractive imaging is the large dynamic range of the diffraction data. Here we report a novel ptychographic experiment using a randomly phased X-ray probe to considerably reduce the dynamic range of the recorded diffraction patterns. Images can be reconstructed reliably and robustly from this setup, even when scatter from the specimen is weak. A series of ptychographic reconstructions at X-ray energies around the L absorption edge of iron demonstrates the advantages of this method for soft X-ray spectromicroscopy, which can readily provide chemical sensitivity without the need for optical refocusing. In particular, the phase signal is in perfect registration with the modulus signal and provides complementary information that can be more sensitive to changes in the local chemical environment.
叠层术是一种扫描衍射成像技术，它可以成功地恢复样品传输函数和照明探针的模和相位。在衍射成像中，一个常见的实验难点是衍射数据的动态范围很大。在这里，我们报告了一种使用随机相位 X 射线探针的新型叠层术实验，可以显著减小记录的衍射图案的动态范围。即使来自样品的散射很弱，也可以从这个设置中可靠而稳健地重建图像。一系列在铁的 L 吸收边缘附近的 X 射线能量的叠层术重建展示了这种方法在软 X 射线光谱显微镜中的优势，它可以在不需要光学聚焦的情况下轻松提供化学灵敏度。特别是，相位信号与模信号完全对齐，并提供互补信息，对局部化学环境的变化更敏感。
