Predicting ptychography probe positions using single-shot phase retrieval neural network

• DOI: 10.1364/oe.524317
• Publication Date: 2024-08-22T17:00:37Z
• Authors: Ming Du; Tao Zhou; Junjing Deng; Daniel J. Ching; Steven Henke; Mathew J. Cherukara
• Keywords: FOS: Computer and information sciences; I.4.0; Computer Science - Artificial Intelligence; Computer Vision and Pattern Recognition (cs.CV); Computer Science - Computer Vision and Pattern Recognition; FOS: Physical sciences; Physics - Applied Physics; Applied Physics (physics.app-ph); 01 natural sciences; 94A08; Artificial Intelligence (cs.AI); Physics - Data Analysis, Statistics and Probability; 0103 physical sciences; Data Analysis, Statistics and Probability (physics.data-an)

Ptychography is a powerful imaging technique that is used in a variety of fields, including materials science, biology, and nanotechnology. However, the accuracy of the reconstructed ptychography image is highly dependent on the accuracy of the recorded probe positions which often contain errors. These errors are typically corrected jointly with phase retrieval through numerical optimization approaches. When the error accumulates along the scan path or when the error magnitude is large, these approaches may not converge with satisfactory result. We propose a fundamentally new approach for ptychography probe position prediction for data with large position errors, where a neural network is used to make single-shot phase retrieval on individual diffraction patterns, yielding the object image at each scan point. The pairwise offsets among these images are then found using a robust image registration method, and the results are combined to yield the complete scan path by constructing and solving a linear equation. We show that our method can achieve good position prediction accuracy for data with large and accumulating errors on the order of 102 pixels, a magnitude that often makes optimization-based algorithms fail to converge. For ptychography instruments without sophisticated position control equipment such as interferometers, our method is of significant practical potential.