High pulse energy Q-switched laser in MOPA configuration

We report high pulse energy actively Q-Switched fibre laser systems in MOPA and single stage configurations. The system was comprised of a Q-Switched master oscillator and power amplifier in either GTwave or end pumped fibres. A number of different fibre lengths and core diameters were used to explore the laser capabilities. A Q-Switched master oscillator operating at 10 kHz repetition rate with typical pulse durations of 40-50 ns at ~ 1070 nm is demonstrated. The laser operation was investigated for pulse repetition rate from 10 to 100 kHz for higher average output powers. After the power amplifier pulse energies as high as 1.1 mJ were obtained.