大模场面积光纤激光器79.4 W单横模输出

 采用光纤缠绕方法，对国产大模场面积多模光纤激光器缠绕前后的输出性能进行了对比研究。将光纤激光器输出端在半径为65 mm的圆筒上缠绕两圈后，获得了单横模输出。光纤缠绕前后，激光器的光束质量因子由1.24减小为1.06，斜率效率由64.7％减小为54.3％。当泵浦功率为149 W时，缠绕前后的输出功率分别为94.7 W和79.4 W。虽然缠绕后功率有所减小，但激光亮度增加了15％。同时对实验所用光纤的缠绕损耗进行了理论计算，实验结果与理论计算值符合得较好。

79.4 W single-transverse-mode output of large-mode-area fiber laser

A homemade large-mode-area(LMA) multimode fiber before and after coiling was studied contrastively in the experiment.Single-transverse-mode output was achieved when the fiber laser was coiled around a mandrel of 65 mm radius.After coiling,beam quality factor of the laser droped from 1.24 to 1.06 and slope efficiency droped from 64.7% to 54.3%.When the launched pump power was 149 W,the corresponding output power was 94.7 W and 79.4 W,respectively.However,the brightness of the coiled fiber laser was 1.15 times that of the uncoiled.Coiled modal losses of different modes were also calculated for the fiber employed in the experiment.The measured results agree well with the calculated ones.