We build a compact ultrafast Er-doped fiber laser based on the tin selenide (SnSe) saturable absorber (SA). Stable continuous-wave and Q-switched mode-locking operation states are realized. By utilizing the time-stretch dispersive Fourier transform, we explore the distinct evolution process of the Q-switched mode-locking operation in a SnSe SA modulated ultrafast Er-doped fiber laser from a real-time horizon. The real-time spectrum displays an interesting breathing process. Inside a single Q-switching envelope, the real-time spectra exhibit entirely different profiles, intensities and bandwidths. Our results can facilitate the understanding of the intrinsic mechanism of the Q-switched mode-locking pulse dynamics in ultrafast fiber lasers.

我们构建了基于硒化锡 (SnSe) 可饱和吸收体 (SA) 的紧凑型超快掺铒光纤激光器。实现了稳定的连续波和 Q 开关锁模操作状态。通过利用时间拉伸色散傅立叶变换，我们从实时范围探索了 SnSe SA 调制的超快掺铒光纤激光器中 Q 开关锁模操作的独特演变过程。实时频谱显示了一个有趣的呼吸过程。在单个 Q 开关包络内，实时光谱表现出完全不同的轮廓、强度和带宽。我们的结果有助于理解超快光纤激光器中调Q锁模脉冲动力学的内在机制。