Improved Three-Dimensional Reconstructions in Electron Ptychography through Defocus Series Measurements
Abstract
A detailed analysis of ptychography for 3D phase reconstructions of thick specimens is performed. We introduce multi-focus ptychography, which incorporates a 4D-STEM defocus series to enhance the quality of 3D reconstructions along the beam direction through a higher overdetermination ratio. This method is compared with established multi-slice ptychography techniques, such as conventional ptychography, regularized ptychography, and multi-mode ptychography. Additionally, we contrast multi-focus ptychography with an alternative method that uses virtual optical sectioning through a reconstructed scattering matrix (-matrix), which offers more precise 3D structure information compared to conventional ptychography. Our findings from multiple 3D reconstructions based on simulated and experimental data demonstrate that multi-focus ptychography surpasses other techniques, particularly in accurately reconstructing the surfaces and interface regions of thick specimens.
Cite
@article{arxiv.2406.01141,
title = {Improved Three-Dimensional Reconstructions in Electron Ptychography through Defocus Series Measurements},
author = {Marcel Schloz and Thomas C. Pekin and Hamish G. Brown and Dana O. Byrne and Bryan D. Esser and Emmanuel Terzoudis-Lumsden and Takashi Taniguchi and Kenji Watanabe and Scott D. Findlay and Benedikt Haas and Jim Ciston and Christoph T. Koch},
journal= {arXiv preprint arXiv:2406.01141},
year = {2024}
}