The theoretical research on fundamental mode 20/400-μm fiber laser for beam propagation application

摘要

A theoretical research of fiber laser in single mode operation was presented to evaluate laser targetingcharacteristics, namely, the beam propagation application. The beam propagation efficiency (BPE) was chosenas the factor to assess the performance of the lasers. Many parameters were studied about their impacts on BPE,including the lens parameters and the transmitting distance. As a result, it was found that the defocus quantity(DQ) valve had a huge impact on beam propagation performance. Given a proper DQ value, the BPE can reacha near limit value. By comparing the BPE performances under different transmission distances, we concludedthat when target radius was set to be 5 cm, the ideal state (BPE＞90%) of beam propagation can be achievedwithin a certain distance of 7 km.