Extending the Computable Depth Range in Electron Ptychography using Event-Converted Data.

Abstract

Iterative multislice electron ptychography enables depth sectioning but its range is constrained by the real-space patch imposed by detector sampling. Reconstruction using converted 4D-STEM patterns into electron-event lists decouples the model's reciprocal-space sampling interval from detector pixels size, reducing data volume, and enabling event-based loss function evaluation. The effect of patch size to the computable depth range, and the validity of the proposed method were demonstrated by simulation. The experimental demonstration on SSZ-13 zeolite shows improved reconstruction quality with preserved depth profiles; under 4× detector binning, reconstruction quality and depth sectioning are retained by selecting a finer reciprocal-space sampling interval, thereby extending the computable depth range without sacrificing angular coverage.