phaser: a unified and extensible framework for fast electron ptychography

We present phaser, an open-source Python package that provides a unified interface to both conventional and autodifferentiation-based ptychographic algorithms. Features such as mixed-state probe, probe position correction, and multislice ptychography make experimental reconstructions practical and robust. Reconstructions are specified in a declarative format and can be run from a command line, Jupyter notebook, or web interface. Multiple computational backends are supported to provide maximum flexibility. We report reconstruction success for a variety of experimental datasets, and detail the effects of regularization on convergence and reconstruction quality. Reconstruction speed is benchmarked for single-slice and multislice reconstructions and compared to state-of-the-art packages. The software promises to speed the application and development of ptychographic methods for materials science.