The petawatt laser of ELI ALPS: reaching the 700 TW level at 10†Hz repetition rate.

Performance of the novel high repetition rate HF-PW laser system of ELI ALPS is presented in its first operation phase at 400 TW and 700 TW levels. Long-term operation was tested at 2.5 and 10 Hz repetition rates, where an exceptional 0.66% and 1.08% shot-to-shot energy stability was demonstrated, respectively. Thorough spatio-spectral and temporal measurements confirmed high quality output pulses with a Strehl ratio of >0.9 after compression at both repetition rates. Amplified pulses with an unprecedentedly high 240 W average power were reached for the first time from a PW-class amplifier chain by using novel pseudo-active mirror disk amplification-based pump lasers.