The 8th International Conference on Matter and Radiation at Extremes (ICMRE2025)

     Two-dimensional shock wave velocity diagnostics play a critical role in high-energy-density physics, inertial confinement fusion, and related fields. The planar morphology and uniformity of the velocity field reflect microscopic inhomogeneities within the wave-bearing medium, necessitating quasi-continuous 2D diagnostics. While conventional 1D line-imaging VISAR is well-established, it lacks spatial resolution for wavefront flatness measurements. Traditional 2D VISAR systems employing gated CCD cameras are limited to single-frame acquisition, failing to achieve continuous temporal resolution. To address these challenges, this study proposes a compressed ultrafast imaging (CUP)-enhanced CUP-VISAR technique for time-resolved 2D velocity field characterization. Preliminary numerical simulations and online experiments validated the feasibility of this method, successfully capturing over seven temporally evolving 2D interferograms. 

     To enhance signal reconstruction quality and explore the technique’s applicability under limited temporal sampling, this work optimized encoding schemes, distortion correction, and blur suppression. Deep learning-based encoding optimization demonstrated superior reconstruction performance, while blur suppression improved the signal-to-noise ratio. The temporal resolution limit of the current optical configuration was determined to be 10 ps, enabling the reconstruction of 40 sequential 2D velocity fields. Linear velocity evolution profiles extracted via dimensionality reduction align with 1D-VISAR diagnostic results, confirming method reliability. These advancements provide a robust framework for high-temporal-resolution shock wave diagnostics and offer new insights for resolving spatial-temporal coupling challenges in dynamic compression experiments. 
 

Shock wave diagnostics,Compressed ultrafast imaging (CUP),CUP-VISAR