Oleh Melnyk, Helmholtz Munich: Understanding gradient methods for blind #ptychography
[#xray #imaging #phaseretrieval]

Scanning technique with overlapping illuminations, to invert far-field intensities into near-field amplitude and phase, and recover both object and illumination

But … why does it work?

Combining in-line #holography with coherent diffractive imaging #CDI
- “phase retrieval for adults”
- refractive object (Wittwer et al, Optica 2022)
-ptychographic iterative engine [#ptychography #PIE] instead of empty beam division
- range constraints, homogeneity

#Physics #CornellUniversity (2021)
> The highest-resolution #image of #atoms so far has been captured, breaking a record set in 2018.

> They used a technique called #ptychography, in which they used an #electron #microscope to analyse the crystal by calculating the angles of scattered electrons to work out the shape of the atoms that scattered them.
> The blurring in the current image comes from the movement of the atoms themselves.
https://www.newscientist.com/article/2279115-this-is-the-most-detailed-look-at-individual-atoms-ever-captured/