2μm掺铥光纤激光器连续和调Q运转的实验研究

摘要

采用二色镜和可变透过率腔镜作为谐振腔,实现了790 nm 半导体激光器端面泵浦下的双包层掺铥光纤激光器的连续和调 Q 运转。连续激光运转实验结果表明,在光纤长度和泵浦功率固定时,增益光纤存在激光输出功率最大情况下的最佳输出透过率,在70%最佳透过率时,得到激光中心波长1930 nm、输出功率5.9 W,斜率效率为46%。采用石墨烯分散液作为可饱和吸收体,插入增益光纤与输出镜之间,实现了掺铥光纤激光器的稳定被动调 Q 运转。当泵浦功率为3.4 W 时,获得最大平均输出功率为39 mW,对应的脉冲宽度为0.9μs,脉冲重复频率为67 kHz,单脉冲能量为210 nJ；平均输出功率、脉冲宽度与泵浦功率近似呈线性关系。%With a dichroic mirror and a variable transmittance mirror as a resonant cavity,this paper realizes the continuous and Q-switching of a double-clad Tm3 +-doped fiber laser pumped by a 792 nm laser diode.The experimental results show that the optimal output transmittance of the gain fiber exists when the pump power and fiber length are fixed and the laser power output is the largest.With 70% of the optimum transmittance,the obtained laser center wavelength is 1 930 nm,its output power is 5.9 W and the corresponding slope efficiency is 46%.Then it conducts the stable passive Q-switching of the fiber laser by u-sing graphene dispersion liquid as a saturable absorber and inserting it between the gain fiber and the output mirror.When the pump power rises to 3.4 W,it obtains the maximum average output power of 39 mW with the corresponding pulse width of 0.9 μs,pulse repetition rate of 67 kHz and single pulse energy of 210 nJ.In addition,the average output power and pulse width are approximately linear with the incident pump power.