研究了2 μm掺Tm耗散孤子光纤激光器在大能量下产生的调制不稳定性, 通过计算耗散孤子锁模的动力学过程, 分析高峰值功率条件下非线性效应对光脉冲特性的影响.通过在环形腔内引入色散补偿光纤和增大模场半径的方式增大腔内净正色散、减小腔内自相位调制效应.针对输出光脉冲线性啁啾较大的特点, 采用46.83 m的大模场光纤对输出光脉冲进行腔外压缩, 最终得到了峰值功率为17.1 kW、脉冲宽度为169 fs的稳定光脉冲输出.

The modulation instability generated by 2 μm dissipative soliton fiber laser under high peak power is studied. The effect of nonlinear effects on the optical pulse characteristics is analyzed by calculating the dynamic process of the dissipative soliton modelocked model. By introducing the dispersion compensation fiber into the annular cavity and adding the radius of the mode field, the net positive dispersion is enlarged and the selfphase modulation effect is reduce in the cavity. Aiming at the larger linear chirp pulse output, 46.83 m large mode area fibers is taken to compress out of cavity. Finally the stable pulse output with peak power of 17.1 kW and pulse width of 169 fs is obtained.