0.85 PW laser operation at 3.3 Hz and high-contrast ultrahigh-intensity λ = 400 nm second-harmonic beamline.

Abstract

We demonstrate the generation of 0.85PW, 30fs laser pulses at a repetition rate of 3.3Hz with a record average power of 85W from a Ti:sapphire laser. The system is pumped by high-energy Nd:glass slab amplifiers frequency doubled in LiB3O5 (LBO). Ultrahigh-contrast λ=400 nm femtosecond pulses were generated in KH2PO4 (KDP) with >40% efficiency. An intensity of 6.5×1021 W/cm2 was obtained by frequency doubling 80% of the available Ti:sapphire energy and focusing the doubled light with an f/2 parabola. This laser will enable highly relativistic plasma experiments to be conducted at high repetition rate.