采用布拉格光纤光栅作为谐振腔,实现了 980nm半导体激光器端面泵浦下的双包层掺镱光纤激光器的连续和调Q运转.连续激光实验结果表明,在泵浦功率固定时,增益光纤存在激光输出功率最大情况下的最佳长度,当泵浦功率增大时,最佳增益光纤长度也随之增加.采用石墨烯分散液作为可饱和吸收体,插入增益光纤与布拉格光纤光栅之间,实现了光纤激光器的稳定被动调Q运转.当泵浦功率为2.87 W时,得到了最小脉冲宽度33 ns、重复率38.5 kHz的脉冲序列;随着泵浦功率进一步增大,出现不稳定的调Q锁模现象.

With fiber Bragg grating as resonant cavity,it was realized for the continuous and Q-switched function of double-clad Yb3+-doped fiber laser whose end pumped by a semiconductor laser of 980nm wavelength. The experimental results of continuous laser showed that the gain fiber exists an optimal length when the pump power is fixed and laser power output biggest;As the pump power increases,the best gain fiber length increases too.The stable passive Q-switching function of the fiber laser was realized by using graphene dispersion liquid as a saturable absorber and inserting it between gain fiber and fiber Bragg grating. At the pump power of 2.87 W,the pulse sequence with minmum pulse width of 33 ns and repetition rate of 38.5 KHz was obtained. As the pump power increased further,the instable Q-swithed mode locking occurred.