Dynamic Behaviors of Pulsating Noise-like Pulses in an Ultrafast Fiber Laser

In this study, we demonstrate the generation and observation of noise-like pulses (NLPs) with unique pulsating characteristics in an ultrafast fiber laser. Furthermore, these NLPs display distinct periodic intensity modulation during temporal evolution, and the corresponding shot-to-shot spectra based on the dispersive Fourier transform (DFT) method exhibit chaotic characteristics with random variable envelopes in each period. Notably, the pulsating period of these NLPs decreases with the increment of pump power. Moreover, both the average output power and pulse energy show a clear linear growth trend as the pump power is raised. Numerical simulations are further conducted to validate these experimental findings. This work will enrich the study of NLPs and pulsation dynamics and provide valuable insights for the development of ultrafast fiber lasers.