光纤弯曲对掺镱光纤激光器光束质量的影响

通过改变F-P腔全光纤激光器中的光纤盘绕半径,对输出激光光束质量进行了研究.搭建了百瓦级全光纤激光器.最大泵浦功率为436 W的条件下,获得了300 W波长1 080 nm的激光输出.光束质量M2=1.13.光-光转换效率为69%.理论分析并计算了20/400 m大模场面积双包层光纤中的两种导波模式LP01模和LP11模沿光纤径向的功率分布和弯曲损耗;利用光纤弯曲选模方法,实验上探究了光纤弯曲半径对输出激光模式及光束质量的影响.实验发现,通过光纤弯曲方式可以有效地消除高阶模式,再经过包层光剥除可以获得更好的光束质量M2=1.06.

Fiber bending impacts on beam quality of Yb- doped fiber laser

By changing the fiber coil radius of F-P cavity all-fiber laser, the output power of the laser in the cladding and the beam quality were studied. A hundreds-watts class all-fiber laser with the output power of 300 W and wavelength of 1 080 nm was build when the maximum pump power was 436 W. The beam quality was tested of M2=1.13 and optical-optical conversion efficiency was 69%. The radial power distribution of the fiber guided wave modes in 20/400 m large mode area double-clad fiber was analyzed. Also the fiber bend loss of two guided wave modes LP01 and LP11 was calculated. By fiber bending mode selection method, the fiber bending impact on the beam quality was theoretically and experimentally studied. It is found that, fiber bending mode can effectively eliminate high-order guided wave mode LP11 and a better beam quality factor M2=1.06 is obtained through stripping the light in fiber clad after fiber bending.