Fibre pulsed lasers are increasingly being adopted as the laser of choice in a number of industrial applications, such as micromachining, drilling and marking. In peak-power-driven applications, such as marking, it is essential to retain high peak powers (in excess of 2.5 to 5 kW) at high repetition rates in order to achieve faster character marking and increased throughput.
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.