光纤包层中的弱光探测技术

Low light detection technique in cladding of optic fiber

设计了一种用于探测光纤激光器系统中有源光纤中残余的弱泵浦光的方法。采用两种光纤探针对剥离涂覆层的有源光纤以及保留涂覆层的光纤进行了包层泄漏光的测试,优选出锥形探针作为弱光探测的光纤探针,并用该探针测得泄漏光与包层残余泵浦光的功率关系,发现二者呈线性关系并有对应的比例系数。通过该光纤探针的方法可实现快速确定有源光纤在激光器中的使用最佳长度,避免传统方法中对有源光纤进行多次切割、熔接再测试等操作,极大地提高了测试效率并降低了测试成本。试验同时发现,光纤探针在剥离涂覆层光纤上的探测效果优于未剥离涂覆层的光纤探测效果。

Technique of residual cladding pump light detection in active fiber was researched, which was used in assembling the fiber laser system. With this technology, a fiber probe was used to detect the pump light leaking from the cladding with fiber＇s coating on and stripping. It＇s found that there was a linear relationship between leaking light power and pump light power, and the proportionality factor was measured. Therefore, it does not need to cut and fuse the active fiber for many times to get the best length of active fiber, and it can save the measuring period and experiment expense a lot. Two types of fiber probes were used, one was taper fiber probe and the other was ramp plane fiber probe. The testing results of low light using these two fiber probes were given, and it＇s found that taper fiber probe is better than ramp plane fiber probe. In order to check the accuracy of fiber probe, a laser test has been done. By testing the power change before and after cutting off optic fiber, and by testing the power via fiber probe at the same position as the cut off point, it proves that fiber probe can well predict the residual pump light.