Open AccessHard X‐ray ptychography for optics characterization using a partially coherent synchrotron source
Author(s) -
Moxham Thomas E. J.,
Parsons Aaron,
Zhou Tunhe,
Alianelli Lucia,
Wang Hongchang,
Laundy David,
Dhamgaye Vishal,
Fox Oliver J. L.,
Sawhney Kawal,
Korsunsky Alexander M.
Publication year - 2020
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577520012151
Subject(s) - optics , ptychography , physics , wavefront , x ray optics , synchrotron radiation , coherence (philosophical gambling strategy) , fresnel zone , diffraction , x ray , quantum mechanics
Ptychography is a scanning coherent diffraction imaging technique which provides high resolution imaging and complete spatial information of the complex electric field probe and sample transmission function. Its ability to accurately determine the illumination probe has led to its use at modern synchrotrons and free‐electron lasers as a wavefront‐sensing technique for optics alignment, monitoring and correction. Recent developments in the ptychography reconstruction process now incorporate a modal decomposition of the illuminating probe and relax the restriction of using sources with high spatial coherence. In this article a practical implementation of hard X‐ray ptychography from a partially coherent X‐ray source with a large number of modes is demonstrated experimentally. A strongly diffracting Siemens star test sample is imaged using the focused beam produced by either a Fresnel zone plate or beryllium compound refractive lens. The recovered probe from each optic is back propagated in order to plot the beam caustic and determine the precise focal size and position. The power distribution of the reconstructed probe modes also allows the quantification of the beams coherence and is compared with the values predicted by a Gaussian–Schell model and the optics exit intensity.