对基于空间滤波原理的光反馈环形腔光纤激光阵列的被动相干组束技术进行了实验研究。采用自行研制的四路保偏掺镱光纤放大器,建立了二维光纤激光相干组束实验系统,通过同相信号光的有效反馈,实现了各路放大激光的同相输出,获得了稳定的二维远场相干图样,相干对比度达91.7%,相干耦合效率为94.5%。并观测到被动锁相时的多纵模相干输出现象。
Coherent beam combination of Yb-doped fiber laser array is studied experimentally by spatial filtering to passive phase locking.The system of coherent beam combination by Yb-doped fiber amplifiers array in two-dimensional distribution is built.The four polarization maintaining Yb-doped fiber amplifiers are developed.By optical feedback of in-phase signal,the in-phase output of all amplified lasers is achieved and two-dimensional far-field stable interference pattern is obtained.The coherent contrast ratio is up to 91.7% and coherent coupling efficiency is 94.5%.Coherent output of multi-longitudinal modes is also observed in phase locking.