Compact diode-pumped 1.1 kW Yb:YAG Innoslab femtosecond amplifier

We demonstrate a compact diode-pumped Yb:KGW femtosecond oscillator-Yb:YAG Innoslab amplifier master oscillator power amplifier (MOPA) with nearly transform-limited 636 fs pulses at 620 W average output power, 20 MHz repetition rate, and beam quality of Mx2 = 1:43 and M y2 = 1:35. By cascading two amplifiers, we attain an average output power of 1:1 kW, a peak power of 80 MW, and a 615 fs pulse width in a single linearly polarized beam. The power-scalable MOPA is operated at room temperature, and no chirped-pulse amplification technique is used.