High-power master oscillation power amplifier with large-mode-area Yb-doped fiber

In this paper, we report a master-oscillator fiber power amplifier system at 1061 nm by using a 4 m long Yb-doped large mode area (LMA) double-clad fiber as the gain medium. At a repetition rate of 20 kHz and 11 ns pulse width, this amplified laser system emitted average and peak power up to 9.9 W and 43 kW, respectively.