Abstract

Temporal contrast being one of the most important parameters of high intensity pulses was intensively investigated during the last decade. New technologies were developed during this period to suppress amplified spontaneous emission (ASE) (DCPA [1] and temporal filtering with XPW [2]). Applied to Petawatt systems they allow to reach extreme values of temporal ASE contrast of above 10¹¹ for repetitive systems and in combination with plasma mirrors > 10¹⁴ for single shot operation. The mentioned above technology is scalable. For repetitive systems to the level of at least 10¹⁵. It can be also improved for additional nearly four orders of magnitude for single shots. After cancelling ASE next is the pedestal at the leading front that appears to be the main issue. For most of high intensity laser systems this pedestal starts to rise above the ASE level at several tens of picoseconds preceding the pulse peak and grows up to the level of 10⁻⁴ in the vicinity of the pulse maximum. The energy accumulated in the pedestal (and intensity) could be an issue for most of modern laser-matter interaction experiments. Contrary to ASE the origin of these features is poorly investigated and understood.

© 2015 IEEE