150 W high-average-power, single-frequency nanosecond fiber laser in strictly all-fiber format

We demonstrate an all-fiber, single-frequency nanosecond laser with both high peak power and average power based on a master oscillator power amplifier (MOPA) configuration. The MOPA produced a single-frequency pulsed laser with pulse duration of ∼8 ns. The average and peak power were as much as 139.3 W and 1.07 kW, respectively, when the repetition rate was 10 MHz, and 153.1 and 668 W, respectively, when the repetition rate was 20 MHz. Higher output power can be obtained by increasing pump power of the main amplifier.