Single-shot visualization of evolving, light-speed structures by multiobject-plane phase-contrast imaging

We demonstrate a single-shot method of visualizing the evolution of light-speed, laser-generated structures as they propagate over hundreds of Rayleigh lengths (typically >= 10 cm) through a tenuous medium. An ultrashort probe pulse crosses the object's path at a small angle (0 < 5 degrees) and a specific time delay. Copies of the phase-modulated probe are then relay-imaged to separate detectors from selected object planes along the propagation path. A phase-contrast technique based on Kerr effect and nonlinear absorption converts phase to intensity modulation, improving sensitivity in tenuous media. A continuous record of the probe phase modulation along the propagation path is reconstructed. (C) 2013 Optical Society of America