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Flexible ptychography platform to expand the potential of imaging at free electron lasers

Kharitonov, Konstantin ; Mehrjoo, Masoud ; Ruiz-Lopez, Mabel ; Keitel, Barbara ; Kreis, Svea ; Seyrich, Martin ; Pop, Mihai LU and Plönjes, Elke (2021) In Optics Express 29(14). p.22345-22365
Abstract

Ptychography, a scanning coherent diffraction imaging method, can produce a high-resolution reconstruction of a sample and, at the same time, of the illuminating beam. The emergence of vacuum ultraviolet and X-ray free electron lasers (FELs) has brought sources with unprecedented characteristics that enable X-ray ptychography with highly intense and ultra-fast short-wavelength pulses. However, the shot-to-shot pulse fluctuations typical for FEL pulses and particularly the partial spatial coherence of self-amplified spontaneous emission (SASE) FELs lead to numerical complexities in the ptychographic algorithms and ultimately restrict the application of ptychography at FELs. We present a general adaptive forward model for ptychography... (More)

Ptychography, a scanning coherent diffraction imaging method, can produce a high-resolution reconstruction of a sample and, at the same time, of the illuminating beam. The emergence of vacuum ultraviolet and X-ray free electron lasers (FELs) has brought sources with unprecedented characteristics that enable X-ray ptychography with highly intense and ultra-fast short-wavelength pulses. However, the shot-to-shot pulse fluctuations typical for FEL pulses and particularly the partial spatial coherence of self-amplified spontaneous emission (SASE) FELs lead to numerical complexities in the ptychographic algorithms and ultimately restrict the application of ptychography at FELs. We present a general adaptive forward model for ptychography based on automatic differentiation, which is able to perform reconstructions even under these conditions. We applied this model to the first ptychography experiment at FLASH, the Free electron LASer in Hamburg, and obtained a high-resolution reconstruction of the sample as well as the complex wavefronts of individual FLASH pulses together with their coherence properties. This is not possible with more common ptychography algorithms.

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type
Contribution to journal
publication status
published
subject
in
Optics Express
volume
29
issue
14
pages
21 pages
publisher
Optical Society of America
external identifiers
  • pmid:34266001
  • scopus:85109165662
ISSN
1094-4087
DOI
10.1364/OE.426931
language
English
LU publication?
yes
id
a142b82c-2f3d-4eb2-a168-a3aef2af290f
date added to LUP
2021-08-20 09:21:35
date last changed
2024-12-29 11:22:51
@article{a142b82c-2f3d-4eb2-a168-a3aef2af290f,
  abstract     = {{<p>Ptychography, a scanning coherent diffraction imaging method, can produce a high-resolution reconstruction of a sample and, at the same time, of the illuminating beam. The emergence of vacuum ultraviolet and X-ray free electron lasers (FELs) has brought sources with unprecedented characteristics that enable X-ray ptychography with highly intense and ultra-fast short-wavelength pulses. However, the shot-to-shot pulse fluctuations typical for FEL pulses and particularly the partial spatial coherence of self-amplified spontaneous emission (SASE) FELs lead to numerical complexities in the ptychographic algorithms and ultimately restrict the application of ptychography at FELs. We present a general adaptive forward model for ptychography based on automatic differentiation, which is able to perform reconstructions even under these conditions. We applied this model to the first ptychography experiment at FLASH, the Free electron LASer in Hamburg, and obtained a high-resolution reconstruction of the sample as well as the complex wavefronts of individual FLASH pulses together with their coherence properties. This is not possible with more common ptychography algorithms.</p>}},
  author       = {{Kharitonov, Konstantin and Mehrjoo, Masoud and Ruiz-Lopez, Mabel and Keitel, Barbara and Kreis, Svea and Seyrich, Martin and Pop, Mihai and Plönjes, Elke}},
  issn         = {{1094-4087}},
  language     = {{eng}},
  month        = {{07}},
  number       = {{14}},
  pages        = {{22345--22365}},
  publisher    = {{Optical Society of America}},
  series       = {{Optics Express}},
  title        = {{Flexible ptychography platform to expand the potential of imaging at free electron lasers}},
  url          = {{http://dx.doi.org/10.1364/OE.426931}},
  doi          = {{10.1364/OE.426931}},
  volume       = {{29}},
  year         = {{2021}},
}