8.2 μJ 5 ps Yb:KGW-Yb:YAG MOPA system at 1 MHz repetition rate

We demonstrated a master oscillator power amplifier (MOPA) based on Yb: KGW and Yb:YAG crystals at 1 MHz repetition rate without chirped pulse amplification (CPA) technique. The Yb:KGW oscillator delivered 1.28 W, 1.87 ps pulses with a repetition rate of 45 MHz. After an acousto-optic modulator (AOM) as the pulse picker, the repetition rate was reduced to 1 MHz. Subsequently, the seed was sent to Yb:YAG amplifiers and boosted to an average power of 8.2 W with a pulse duration of 4.66 ps, corresponding to a pulse energy of 8.2 mu J and a peak power of 1.76 MW.