Megahertz-rate digital holography system

Given the need for a simple and fieldable diagnostic that can enable the study of ultrahigh-speed phenomena in three dimensions, this work presents experiments and simulations to optimize and demonstrate a digital in-line holography system with an acquisition rate of 1 million frames per second. The system is used to study the collision of a supersonic projectile and its bow shock with 1 mm diameter water droplets. The holograms acquired are three-dimensionally reconstructed and de-twinned to analyze shock wave phenomena in these supersonic impact events and demonstrate the potential of ultrahigh-speed digital holography as a robust technique to probe complex shock wave dynamics and droplet breakup.