title: High-speed two-frame shadowgraphy for velocity measurements of laser-induced plasma and shock-wave evolution.
abstract: We describe a high-speed, two-frame shadowgraph method for the two-dimensional visualization of an expanding laser-induced plasma and shock wave in two time instances. The developed experimental method uses a 30 ps, green-laser, polarized pulse for the direct and delayed illumination separated by a variable time delay in the range from 300 ps to 30 ns. Since the exposed images of a single event are captured with two CCD cameras, the established method enables velocity measurements of the fast laser-induced phenomena within the nanosecond excitation-laser pulse as well as at later times-when the excitation-laser radiation has already ended.
authors.affiliation: Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia. peter.gregorcic@fs.uni‐lj.si
authors.forename: Peter
authors.initials: P
authors.lastname: Gregorčič
authors.forename: Janez
authors.initials: J
authors.lastname: Možina