Ptychography is a coherent diffractive imaging method that uses multiple diffraction patterns obtained through the scan of a localized illumination on the specimen. Until recently, reconstruction algorithms for ptychographic datasets needed the a priori knowledge of the incident illumination. A new reconstruction procedure that retrieves both the specimen's image and the illumination profile was recently demonstrated with hard X-ray data. We present here the algorithm in greater details and illustrate its practical applicability with a visible light dataset. Improvements in the quality of the reconstruction are shown and compared to previous reconstruction techniques. Implications for future applications with other types of radiation are discussed.
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http://dx.doi.org/10.1016/j.ultramic.2008.12.011 | DOI Listing |
Sci Adv
January 2025
Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, 91405 Orsay, France.
Charge transport in materials has an impact on a wide range of devices based on semiconductor, battery, or superconductor technology. Charge transport in sliding charge density waves (CDW) differs from all others in that the atomic lattice is directly involved in the transport process. To obtain an overall picture of the structural changes associated to the collective transport, the large coherent x-ray beam generated by an x-ray free-electron laser (XFEL) source was used.
View Article and Find Full Text PDFSci Adv
January 2025
Department of Physics, University of Arizona, Tucson, AZ 85721, USA.
Nat Commun
December 2024
Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA.
Discontinuous solid-solid phase transformations play a pivotal role in determining the properties of rechargeable battery electrodes. By leveraging operando Bragg Coherent Diffractive Imaging (BCDI), we investigate the discontinuous phase transformation in LiNiMnO within an operational Li metal coin cell. Throughout Li-intercalation, we directly observe the nucleation and growth of the Li-rich phase within the initially charged Li-poor phase in a 500 nm particle.
View Article and Find Full Text PDFJ Xray Sci Technol
December 2024
Henan Key Laboratory of Imaging and Intelligent Processing, Information Engineering University, Zhengzhou, Henan, China.
Background: Coherent diffraction imaging (CDI) is an important lens-free imaging method. As a variant of CDI, ptychography enables the imaging of objects with arbitrary lateral sizes. However, traditional phase retrieval methods are time-consuming for ptychographic imaging of large-size objects, e.
View Article and Find Full Text PDFJ Synchrotron Radiat
January 2025
ESRF - The European Synchrotron, 71 Avenue des Martyrs, 38000 Grenoble, France.
Coherent diffractive imaging experiments often collect incomplete datasets containing regions that lack any measurements. These regions can arise because of beamstops, gaps between detectors, or, in tomography experiments, a missing wedge of data due to a limited sample rotation range. We describe practical and effective approaches to mitigate reconstruction artifacts by bringing uniqueness back to the phase retrieval problem.
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