Contrast improvement at petawatt-class lasers using ultrafast optical-parametric amplification

摘要

With increasing intensities the temporal contrast which is defined as the ratio between the peak-intensity and the intensity at a given time before the maximum, has recently become one of the most critical parameters of modern short-pulse laser systems. In typical laser-plasma experiments the prepulse induces ionization of the target in the nano- to picosecond range prior to the impact of the main pulse resulting in uncontrollable experimental conditions.