A diagnostic system toward high-resolution measurement of wavefront profile

Analysis of wavefront is vital in the process of the inertial confinement fusion (ICF), but there is lack of accurate method to achieve the wavefront image with a high resolution of up to the picosecond (ps) level. The two-dimensional imaging velocity interferometer system for any reflectors (2D-VISAR) can only realize two-dimensional images with a temporal resolution in a nanosecond scale or one two-dimensional image, leading to the difficulties in recovering the high-speed changing process. Although the line-imaging VISAR with a streak camera has a higher temporal resolution of 5 ps, it hardly offers two-dimensional images. In this study, we design a diagnostic system by coupling the line-imaging VISAR and compressed sensing theory to recover the wavefront profile, by which both the two-dimensional and high-temporal resolution wavefront are obtained. A series of original fringe images are firstly processed, and then acquiring data and reconstructing images are simulated, which results in corresponding reconstructed fringe images. The deviation of the resulting images is evaluated to be below 2.1% for the reconstructed shock wave velocities compared to the original shock wave velocities, much lower than the initial velocity, suggesting that the wavefront profile change is successfully recovered, which indicates the diagnostic system for more accurate measurements of the wavefront profile is feasible. This new system is expected to be applied in the field of implosion to provide more extensive information.