Development of an ultrafast laser-driven shock wave microscope

We discuss our recent efforts at the University of Alabama at Birmingham to build a laser-driven shock wave microscope that can image in real time the interaction of high-pressure waves with matter at sub-micron resolution. Using synchronized femtosecond pulses, we create shock waves by focusing our laser pulses on the ablator side of a sample-spacer-ablator design, and use a delayed broadband supercontinuum white light to conduct both time-resolved imaging and spectroscopy on the opposite reflecting side using a high numerical aperture and long working distance microscope objective. Our setup can achieve power densities of around 1,250 GW per square centimeter per pulse using our tunable 1-100 kHz repetition rate laser system that generates laser pulses centered at 1030 nm (or 515 nm when frequency doubled) and having a temporal duration of 250 fs. Furthermore, the single-shot nature of these experiments allows us to map the material properties both spatially with micron resolution, and as a function of the laser-generated shock strength. We will discuss results obtained on samples of hybrid perovskites bulk crystals, thin metallic films of Al, and high entropy alloy AlCoCrFeNi_2.1, along with methods used to disentangle these hyperspectral datasets.