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 $\sim 1064\mathrm{nm}$ 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 $\sim 1\mathrm{W}$, and two double-cladding Yb-doped fiber amplifiers were used to boost the average power of the seed. $>230\mathrm{W}$ average power was achieved for $\sim 1.4\mathrm{\mu s}$ pulses at 100 kHz repetition rate. The optical-to-optical efficiency of the main amplifier is 72.81%.