In this paper, the experimental investigation and theoretical analysis on the soliton rain generated in the Tm-doped fiber laser have been carried out. On the basis of nonlinear polarization rotation technology, the fundamental and harmonic soliton rain pulses were obtained, the influence of net negative dispersion cavity length on the output performances of soliton rain pulse were studied, and the spectral sideband characteristics of soliton rain were numerically analyzed. By comparing the spectra of continuous wave mode-locking and soliton rain states, it can be found that the quasi-periodic modulation exists for the spectral sideband of soliton rain resulted from the complex interaction between the dispersive wave and the soliton wave. The interaction is one of the major factors for the formation of soliton rain. The research results are helpful for the better understanding of the soliton rain dynamics and mechanism in passive mode-locked fiber lasers.

本文对掺m光纤激光器产生的孤子雨进行了实验研究和理论分析。在非线性极化旋转技术的基础上，获得了基本和谐波孤子雨脉冲，研究了净负色散腔长度对孤子雨脉冲输出性能的影响，并对孤子雨的光谱边带特性进行了数值分析。通过比较连续波锁模态和孤子雨态的频谱，可以发现，由于色散波与孤子波之间复杂的相互作用，孤雨谱的边带存在准周期调制。相互作用是形成孤子雨的主要因素之一。