230 W average-power all-fiber-based actively Q-switched fiber master oscillator–power amplifier

We report a high-power all-fiber format pulsed laser source at ~1064 nm in a master oscillator-power amplifier configuration. The seed source is an acousto-optic Q-switched fiber laser with a varied pulse duration and repetition rate. The output power of the oscillator is ~1 W, and two double-cladding Yb-doped fiber amplifiers were used to boost the average power of the seed. >230 W average power was achieved for ~1.4 μs pulses at 100 kHz repetition rate. The optical-to-optical efficiency of the main amplifier is 72.81%.