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Title: Evaluation of partial coherence correction in X-ray ptychography

Coherent X-ray Diffraction Imaging (CDI) and X-ray ptychography both heavily rely on the high degree of spatial coherence of the X-ray illumination for sufficient experimental data quality for reconstruction convergence. Nevertheless, the majority of the available synchrotron undulator sources have a limited degree of partial coherence, leading to reduced data quality and a lower speckle contrast in the coherent diffraction patterns. It is still an open question whether experimentalists should compromise the coherence properties of an X-ray source in exchange for a higher flux density at a sample, especially when some materials of scientific interest are relatively weak scatterers. A previous study has suggested that in CDI, the best strategy for the study of strong phase objects is to maintain a high degree of coherence of the illuminating X-rays because of the broadening of solution space resulting from the strong phase structures. In this article, we demonstrate the first systematic analysis of the effectiveness of partial coherence correction in ptychography as a function of the coherence properties, degree of complexity of illumination (degree of phase diversity of the probe) and sample phase complexity. We have also performed analysis of how well ptychographic algorithms refine X-ray probe and complex coherence functionsmore » when those variables are unknown at the start of reconstructions, for noise-free simulated data, in the case of both real-valued and highly-complex objects.« less
 [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [2] ;  [1]
  1. Univ. College London, London (United Kingdom); Research Complex at Hartwell, Oxford (United Kingdom)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of Oregon, Eugene, OR (United States)
  3. SLAC National Accelerator Lab., Menlo Park, CA (United States); DESY, Hamburg (Germany)
  4. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357; FG02-11ER46831; AC02-05CH11231; AC02-05CH11231, AC03-76SF00515; Contract No. DEAC02- 05CH11231
Published Article
Journal Name:
Optics Express
Additional Journal Information:
Journal Volume: 23; Journal Issue: 5; Journal ID: ISSN 1094-4087
Optical Society of America (OSA)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; phase retrieval; image reconstruction techniques; X-ray imaging
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1215676; OSTI ID: 1221598