Phase Retrieval in py4DSTEM

• Suite of phase retrieval algorithms, including iterative DPC and Parallax

Tutorial dataset from Y Jiang et al, Nature 559, 343 (2018)

User-friendly code

  ptycho = SingleslicePtychographicReconstruction(
      datacube=dataset,
      energy = 80e3,
      semiangle_cutoff = 21.4,
  ).preprocess(
      fit_function = "plane", # de-scan correction
  ).reconstruct(
      max_iter = 8,
      step_size = 0.5,
      gaussian_filter_sigma = 0.3, # A
  ).visualize(
  )

Check out our tutorial notebooks here, and our recent preprint arXiv:2309.05250!
See also poster #1289 by Dr. Stephanie Ribet today!

• Iterative ptychography features:
  • Gradient-descent and projection-set algorithms
  • STEM-specific regularizations
  • Probe-position refinement
  • Hyperparameter tuning using Bayesian optimization
  • Mixed-state reconstructions
  • Single-slice and multi-slice reconstructions
  • Joint ptychographic-tomographic reconstructions
  • Simultaneous reconstructions for electrostatic and magnetic fields