We numerically and experimentally investigate the multi-pulsing mechanism in a dispersion-managed mode-locked Yb-doped fiber laser. Multi-pulsing occurs primarily owing to the inherent filtering effect of the chirped fiber Bragg grating. The spectral filtering effect restricts the spectral broadening induced by self-phase modulation and causes extra loss, leading to a decreased pump power threshold for the multi-pulsing state. Numerical simulations show that multi-pulsing emerges at a lower pump power when the spectral filter bandwidth becomes narrower. In the experiment, the spectral width increases as the net cavity dispersion approaches zero. Pulses with wider spectral widths experience more loss from the spectral filtering effect, leading to a decreased pump power threshold for multi-pulsing. Therefore, the net cavity dispersion also has an impact on the multi-pulsing threshold. Based on this conclusion, we devise a strategy to obtain single-pulsing operation with the shortest pulse width and the highest pulse energy.

中文翻译：

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色散管理锁模掺Yb光纤激光器中啁啾光纤布拉格光栅引起的多脉冲的光谱滤波效应

我们通过数值和实验研究了色散管理锁模 Yb 掺杂光纤激光器中的多脉冲机制。多脉冲的发生主要是由于啁啾光纤布拉格光栅的固有过滤效应。光谱滤波效应限制了自相位调制引起的光谱展宽并导致额外的损耗，导致多脉冲状态的泵浦功率阈值降低。数值模拟表明，当光谱滤波器带宽变窄时，多脉冲出现在较低的泵浦功率下。在实验中，光谱宽度随着净腔色散接近零而增加。光谱宽度较宽的脉冲会因光谱滤波效应而损失更多，从而导致多脉冲的泵浦功率阈值降低。所以，净空腔色散对多脉冲阈值也有影响。基于这一结论，我们设计了一种策略来获得具有最短脉冲宽度和最高脉冲能量的单脉冲操作。