Otto Hans-Jürgen, Stutzki Fabian, Modsching Norbert, Jauregui Cesar, Limpert Jens, Tünnermann Andreas
Opt Lett. 2014 Nov 15;39(22):6446-9. doi: 10.1364/OL.39.006446.
This Letter reports on a fiber-laser system that, employing a 1 m long rod-type photonic-crystal fiber as its main-amplifier, emits a record average output power of 2 kW, by amplifying stretched ps-pulses. A further increase of the output power was only limited by the available laser-diode pump power. The energy of the pulses is 100 μJ, corresponding to MW-level peak powers extracted directly from the fiber of the main amplifier. The corresponding M2 at the maximum output power is <3, due to the onset of mode instabilities. The Letter covers the influence of this effect on the evolution of the beam quality with the output power. The numerical results show that the M2 value settles at around 3, even if the output average power is further increased.
本信函报道了一种光纤激光系统，该系统采用一根1米长的棒状光子晶体光纤作为主放大器，通过放大展宽的皮秒脉冲，实现了创纪录的2千瓦平均输出功率。输出功率的进一步提高仅受可用激光二极管泵浦功率的限制。脉冲能量为100微焦，对应于直接从主放大器光纤中提取的兆瓦级峰值功率。由于模式不稳定性的出现，在最大输出功率下相应的M²<3。本信函探讨了这种效应对光束质量随输出功率变化的影响。数值结果表明，即使输出平均功率进一步提高，M²值也稳定在3左右。
