Real-time tracking of single shockwaves via amplified time-stretch imaging

We report the tracking of single laser-induced shockwaves (SWs) using a real-time all-optical imaging setup based on amplified time-stretch dispersive Fourier transformation. SW propagation is encoded transversally on spatially dispersed ultrashort pulses at a frame rate of 80 MHz, and the technique allows us to record its evolution on μs timescales. We were then able to monitor the slowing down of a single SW and its reflection on a plane surface and also to perform velocity statistics and to evidence SW-to-SW fluctuations. This feasibility study proves time-stretch imaging to be a complementary and particularly adapted method to study SW dynamics and interactions and fast non-repetitive events occurring in laser ablation.