Single-frequency nanosecond pulsed laser with output power of 300 W in all-fiber format

A master oscillator power amplifier(MOPA) structured pulsed Yb fiber laser is set up. The single-frequency pulsed seed, with a repetition rate of 10 MHz, a pulse duration of about 8 ns, and an average power of 0.5 mW, is obtained by externally modulating a continuous wave laser with line width of 20 kHz. The pulsed seed is amplified to 300.8 W of average power with four Yb-doped fiber amplifiers. Further power-scaling of this MOPA structure can be realized since our experiment is only pump-power limited.