2.6 GW, mJ-class high-energy femtosecond laser system based on Yb:YAG single-crystal fiber amplifier

Abstract

High-peak-intensity ultrafast fiber lasers show excellent prospect for ultrafast science and industrial applications. For simplicity as well as efficiency, chirped-pulse amplification (CPA) is an effective technique for the generation of high-energy sources and single crystal fiber (SCF) also shows great potential due to its convenient configuration. In this work, a high-peak-power hybrid CPA pulsed laser system based on a three-stage single-pass end-pumped Yb:YAG SCF amplifier is experimentally demonstrated. The amplification system emitted pulses with the maximum power of 103.2 W at 100 kHz repetition rate and we obtained the compressed output power of 84.2 W, corresponding to the pulse energy of 0.84 mJ. Considering the third order dispersion that induced by the stretcher and the accurate tuning effect for higher-order dispersion compensation of chirped fiber Bragg grating, we have demonstrated a nearly transform limited output pulse duration of 323 fs with the peak power exceeding 2.6 GW. It can be said that we present the results for the first implementation of the shortest pulse duration and highest peak power in such multi-stage Yb:YAG SCF amplifier. The well-preserved beam quality with the measured M² value of 1.22 and 1.29 for the horizontal and vertical directions at the maximum achieved average power. With such outstanding combined features, the demonstrated high-energy ultrafast fiber lasers would enable broad applications.