高功率光纤激光中模式不稳定性现象研究进展

Progress of Study on Mode Instability in High Power Fiber Amplifiers

模式不稳定指高功率光纤激光随着输出功率提升发生的由稳态基模输出突然变为非稳态高阶模式输出的模式突变,会导致光束质量下降,限制着衍射极限光束质量光纤激光输出功率的提升。介绍了高功率光纤激光中模式不稳定现象的产生机理以及相关的实验和理论研究,详细分析了模式不稳定现象的一些性质,总结了解决或抑制高功率光纤激光中模式不稳定现象的方法。最后,对高功率光纤激光模式不稳定现象研究的未来发展趋势进行了初步探讨。

Mode instability （MI） is an abrupt mode change when the average output power increases above a certain threshold power, which results in degradation of beam quality and currently limits the power scaling of diffraction-limited high power fiber laser. The investigation progress on MI in high power fiber amplifiers is introduced in detail. The characteristics of MI are described and the ways to mitigateMI and increase the threshold power are summarized. The development trends of study on MI in high power fiber amplifier are briefly discussed.