Studies on nanosecond laser induced damage to fused fibers

Abstract

The properties of high_peak pulsed laser induced damage to fibers have been investigated by damage experiments. It was found that all of damaged parts are located on fiber endings, and the damage topography fall into three classes: the pit damage, fusion damage and sputtering damage. The experimental setup of laser induced damage to fibers, fiber damage judgment criterions and data processing methods were developed and validated. The zero probability damage threshold was calculated by linear fitting to be 3.85GW/cm2. The processes of laser induced damage to fibers were summarized and the fiber end face damage mechanism was studied. The experimental results indicated that the main factor that makes the fiber end faces susceptible to laser induce damage is the existence of surface imperfections. The nanosecond laser induce damage to fiber end faces are detected experimentally; the central areas of input end faces are damaged probably because the input laser beam is Gaussian. So the use of uniform beam for injecting the fiber is favorable to the laser-induced damage resistance.