脉冲激光诱导光纤损伤的测试方法

 针对传能光纤的高峰值功率激光损伤过程，研究了光纤损伤测试方法。实验装置搭建中增加了定位孔，有利于激光注入光纤对准；分别采用刀口法和CCD法对入射光束不同截面处光斑大小进行了测量，两种方法的测量结果基本一致。参考GJB1487-92激光光学元件测试方法和ISO11245光学表面的激光诱导损伤阈值测试方法，采用N-ON-1损伤测试和有效光斑面积计算方法对芯径为400 μm的石英包层阶跃折射率石英光纤进行了损伤阈值测试。实验发现：光纤损伤部位全部为入射端面，利用200倍显微镜观察光纤端面，出现明显永久性损伤点。最后采用统计学原理和线性拟合等方法得出测试光纤的端面零概率损伤阈值为3.85 GW/cm²。

Experimental measurement of pulsed-laser induced damage to fibers

In the experiment of laser induced damage to optical fiber, a positioning hole was added in the experimental setup, which was useful to alignment of the laser beam. The beam size was measured in the knife edge way and the CCD way, the results of the two ways were in agreement. The ways of judgment and test were investigated, and the method to calculate zero probability damage thresholds was introduced. Reference on “GJB1487-92 test method for laser optical elements” and “ISO11245 test method for laser radiation induced damage threshold of optical surfaces”, the experimental setup of laser induced damage to fibers, fiber damage judgment criterions and data processing methods were introduced and validated. The damage threshold tests of fused silica, step-index, and multimode fiber were c