Suppression of nanosecond prepulses from regenerative amplifier and multipass amplifiers in the SULF-1PW laser

In this research, we report the latest progress in the suppression of nanosecond prepulses from regenerative amplifier and multipass amplifiers in the SULF-1PW laser.The prepulse generated from the Pockels cell (PC) in a regenerative amplifier is delay-shifted by enlarging the distance between the PC and the nearby cavity mirror, and then removed by the extra pulse pickers outside the regenerative amplifier.The prepulses arising from multipass amplifiers are also further suppressed by adopting a novel amplifier configuration and properly rotating the Ti:sapphire crystals.After the optimizations, the temporal contrast on a nanosecond time scale is promoted to be better than a contrast level of 10 -9 .This research can provide beneficial guidance for the suppression of nanosecond prepulses in the high-peak-power femtosecond laser systems.