Aberration correction is an important aspect of modern high-resolution scanning transmission electron microscopy. Most methods of aligning aberration correctors require specialized sample regions and are unsuitable for fine-tuning aberrations without interrupting on-going experiments. Here, we present an automated method of correcting first- and second-order aberrations called BEACON which uses Bayesian optimization of the normalized image variance to efficiently determine the optimal corrector settings. We demonstrate its use on gold nanoparticles and a hafnium dioxide thin film showing its versatility in nano- and atomic-scale experiments. BEACON can correct all first- and second-order aberrations simultaneously to achieve an initial alignment and first- and second-order aberrations independently for fine alignment. Ptychographic reconstructions are used to demonstrate an improvement in probe shape and a reduction in the target aberration.
@article{arxiv.2410.14873,
title = {BEACON -- Automated Aberration Correction for Scanning Transmission Electron Microscopy using Bayesian Optimization},
author = {Alexander J. Pattison and Stephanie M. Ribet and Marcus M. Noack and Georgios Varnavides and Kunwoo Park and Earl Kirkland and Jungwon Park and Colin Ophus and Peter Ercius},
journal= {arXiv preprint arXiv:2410.14873},
year = {2024}
}