A 325-W-average-power fiber CPA system delivering Sub-400 fs pulses

A high-average-power Yb-doped fiber chirped-pulse amplification system is presented. Compressed average power of 325 W at 40 MHz repetition rate corresponding to 8.2 mu J pulse energy is extracted. Compression in a highly efficient dielectric-grating-based compressor yields pulses as short as 375 fs, resulting in 22 MW of peak power.