掺Yb^3+双包层光纤激光器的自脉冲行为分析

Analysis of the self pulsing behavior of Yb^(3+)-doped double clad fiber laser

为了对掺 Yb^(3+)双包层光纤激光器的自脉冲行为进行系统的理论研究,采用数值模拟方法,对光子数密度和反转粒子数密度随时间及抽运功率的变化、阻尼系数与后腔镜的反射率和掺杂粒子浓度的关系,以及光纤本身固有振荡频率随后腔镜反射率的变化进行了理论分析。结果表明,随抽运功率的增加,振荡频率增加,振幅度减小;降低输出端的反馈和粒子的浓度可以抑制自脉冲现象。另外提出了抑制光纤激光器自脉冲的措施,为设计掺 Yb^(3+)双包层光纤激光器提供了理论依据。

In order to investigate the effect of self-pulsing of Yb^3＋ -doped fiber laser, the variation of photon density and inversed populations with pump power, the relationship among the damping coefficient, the output coupling reflectivity and doped particle concentration,and the variation of inherent oscillation frequency with output coupling refleetivity were simulated. The results show that the self-pulsing effect can be compressed with the decrease of the feedback of the output end and the increase of the doping concentration. Some measures to compress the self pulse of a fiber laser were put forward, providing a theoretical base for the design of Yb^3＋ -doped fiber lasers.