New progress of high power narrow-linewidth fiber lasers

High power narrow-linewidth fiber lasers have been highly desired for various applications. In this paper, we presented new considerations of high power narrow-linewidth fiber amplifiers operating within 1030 similar to 1060 nm by using newgeometry active fiber, and the power-breakthrough operating at 1050 nm was achieved. We also reported our recent achievements on power scaling of high-power narrow-linewidth fiber lasers which operates within 1060 similar to 1080 nm based on system-optimized step-index and confined-doped active fibers, including linear-polarized and stochastic-polarized ones. Meanwhile, our new progress on special designed active fibers assisted high power fiber amplifiers with sub-GHz to within 1.5 GHz were demonstrated. Besides, the basic considerations of end-reflection on the SBS and SRS effects will be discussed, which provide a new insight for the suppression of SBS and SRS effects.