Evaluation of partial coherence correction in X-ray ptychography.

Area of Science:

• X-ray optics
• Coherent X-ray Diffraction Imaging (CDI)
• Ptychography

Background:

• Coherent X-ray Diffraction Imaging (CDI) and X-ray ptychography require high X-ray spatial coherence for quality reconstructions.
• Synchrotron sources often have limited partial coherence, reducing data quality and speckle contrast.
• The trade-off between X-ray source coherence and flux density for weak scattering materials remains an open question.

Purpose of the Study:

• To systematically analyze the effectiveness of partial coherence correction in ptychography.
• To investigate the influence of illumination coherence, probe complexity, and sample complexity on correction effectiveness.
• To assess the ability of ptychographic algorithms to refine unknown probe and coherence functions during reconstruction.

Main Methods:

• Simulated noise-free data for ptychographic reconstructions.
• Analysis of partial coherence correction effectiveness across varying coherence properties.
• Evaluation of algorithm performance with diverse illumination and sample phase complexities.

Main Results:

• Partial coherence correction effectiveness is dependent on the interplay between illumination coherence, probe phase diversity, and sample phase complexity.
• Ptychographic algorithms demonstrate capability in refining unknown probe and complex coherence functions.
• The study provides a framework for optimizing experimental parameters in ptychography.

Conclusions:

• Partial coherence correction is a viable strategy in ptychography, but its effectiveness is nuanced.
• Understanding the relationship between coherence, probe, and sample is crucial for successful X-ray imaging.
• Ptychography algorithms offer robust solutions for handling partial coherence and refining illumination parameters.