Development of a 67.8 W, 2.5 ps ultrafast chirped-pulse amplification system based on single-crystal fiber amplifiers

We demonstrate a high-power, high-energy chirped-pulse amplification (CPA) system based on three Yb:YAG amplifiers and a chirped-volume Bragg grating (CVBG). With an all-fiber laser as the seed light, a Yb:YAG rod amplifier and two Yb:YAGsingle-crystal fiber (SCF) amplifiers as the amplification stages, a laser power of 96W at 200 kHz repetition rate corresponding to a pulse energy of 0.48 mJ has been generated. The stability of different output power has been measured and compared. To the best of our knowledge, this is the first report on a stable 100W-level laser with sub-mJ pulse energy based on SCF. The beam quality M-2 of different output lasers has also been measured, which is below 1.55 when the output power is 92W. The amplified laser is seeded into the CVBG to be compressed, and a compression efficiency of 0.724 has been obtained with an output power of 67.8W and pulse duration of 2.5 ps. The ultrafast CPA system delivering high pulse energy (sub-mJ) with hundreds of kHz repetition rate is expected to be used as the driving source of high-flux high-harmonic generation after further compression. (C) 2020 Optical Society of America