Enhanced single-shot inversion of the diffraction phase problem with the diffusion model

We present an advance in computational solution of the crystallographic “phase problem”. The diffraction data used in Bragg Coherent Diffraction Imaging experiments are “oversampled” because there are many more measurement points than unknown pixel values. Their inversion in the presence of noise often leads to multiple solutions. Here we reexamine diffraction data measured previously on thin films of superconducting La1.93Sr0.07CuO4 material on its (103) Bragg peak with bursts of single pulses of X-ray Free Electron Laser radiation. We demonstrate that the diffusion model is able to filter these solutions sufficiently to give reproducible images. The images show nanometer-sized regions of material phase-shifted with respect to each other. These are expected from the use of the Atomic Layer Epitaxy methods used to prepare the samples.