High Spatiotemporal Resolution Imaging and Transient Diagnostics

This research area is dedicated to developing high spatiotemporal resolution diagnostic methods for ultrafast laser processing. At the optical level, a suite of diagnostic platforms—including pump-probe, ultrafast shadowgraphy, interferometry, and schlieren methods—is established to visualize surface and near-surface transient processes such as plasma evolution, shockwave propagation, material ejection, and phase front movement with nanometer-picosecond resolution. For probing internal structures, advanced high spatiotemporal resolution X-ray phase-contrast imaging techniques are developed utilizing large-scale synchrotron facilities like Spring-8. These enable in-situ, penetrating observation of internal dynamic behaviors during laser processing, including melt pool flow, pore formation, crack propagation, and internal phase transitions, thereby constructing a complete spatiotemporal picture of laser-matter interactions.