Development of a 10 mJ-level optically synchronized picosecond Yb:KYW amplifier at 1040 nm for OPCPA pumping

Abstract

We report on a novel 10 mJ-level diode-pumped Yb:KYW amplifier at 1040 nm, which generates picosecond pulses at a repetition rate of 10 Hz. It will be used in the front end of a petawatt laser system for pumping an optical parametric amplifier (OPA) for contrast enhancement. For synchronization purposes the amplifier is seeded by pulses that are derived from the femtosecond oscillator. After stretching by a volume Bragg grating and amplification in a double stage fiber amplifier the pulses are injected into the Yb:KYW regenerative cavity. Finally, the pulses are compressed to 1 ps before preparing pump pulses for the OPA by second harmonic conversion.