Theoretical and experimental study on kW all fiber laser

kW-class all-fiber laser was designed by employing master oscillator power amplifier (MOPA) configuration. Power output and distribution, mode controlling by bending, thermal distribution of active fiber in cooling condition were numerically analyzed. The fiber laser based on our design was built up. In the experiment, 1060 W continuous laser was obtained with a total pumped power of 1436 W. The optical-optical conversion efficiency was 73.8% and the beam quality M2 was less than 1.6. We preliminarily discussed the difference between the experimental results and theoretical design.