被动锁模掺铥光纤激光器特殊形状脉冲的研究

Experimental investigate in special shape pulses of passively mode-locked thulium-Doped fiber laser

通过非线性偏振旋转被动锁模掺铥光纤激光器的研究发现,该激光器可以实现特殊形状类h型脉冲输出。进一步研究表明,类h型脉冲继承了耗散孤子共振随着抽运功率的增加脉冲不会破裂、脉冲宽度和能量单调增加的特点,避免了传统孤子的局限性。因此,利用非线性偏振旋转所形成的人造可饱和吸收体,实现了重复频率为19.8MHz、信噪比为56dB的高稳定性锁模脉冲输出。实验结果对2pm波段非线性偏振旋转光纤激光器锁模脉冲动力学特性的研究具有一定产考价值。

Pulse generations in fiber lasers have attracted considerable attention,especially for what is realized by passive mode-locking technologies.Driven by rich and complex dynamics,pulses of various shapes have been realized,but it can be expected that some new pulses are still waiting to be discovered and deployed.Moreover,the study of special shape pulse can enrich the research content of nonlinear impulse dynamics and further promote the development of nonlinear impulse dynamics.We report on a type of h-shape pulse in a passively mode-locked thulium-doped fiber laser with 2μm was found by studying the laser using nonlinear polarization rotation technique.The h-shape pulse inherits the characteristics of dissipative soliton resonance such as large pulse duration,low pulse peak power,and high pulse energy,and can also avoid the limitations of traditional solitons.The artificial saturated absorber formed by nonlinear polarization rotation achieves a highly stable h-shape mode-locked pulse output with a repetition rate of 19.8 MHz and a signal-to-noise ratio of 56 dB.These results will be helpful for the investigation of pulses dynamics of 2μm mode-locked fiber laser.