High-fidelity ptychographic imaging of non-repeatable plasma dynamics

Laboratory scale gaseous plasma events offer a rich environment for the study of ionization, energy transfer, and non-equilibrium dynamics, whose understanding plays a critical role in wakefield accelerators, inertial confinement fusion, and plasma ignition devices. Probing these dynamics however, has been historically difficult due to their weak absorption of visible light and inherently challenging spatial and temporal scales. Recent advances in computational imaging have opened the door for advanced forms of plasma diagnostics with techniques such as single-shot ptychography (SSP), however fidelity challenges and reduced resolution have limited the application of SSP to non-repeatable plasma dynamics. Here we introduce a near-field implementation of SSP that delivers enhanced fidelity and resolution, as well as improved robustness to noise compared to far-field methods, verified though systematic experimental and numerical comparisons. Using this method, we demonstrate, for the first time, ptychographic imaging of non-repeatable plasma dynamics through the analysis of a full temporal trace of an electrostatic discharge event. These results establish near-field SSP as a powerful plasma diagnostic tool, opening the pathway towards 3D, hyperspectral, and single-shot ultrafast motion-picture ptychographic imaging, of complex plasma systems.