Symbiotic coexistence of noise-like pulses

Noise-like pulse (NLP) can split and then self-assemble into dynamic bound states, named NLP polymer. Here, we reported the first observation, to the best of our knowledge, of the buildup process of bound NLPs in all-normal-dispersion Yb-doped fiber lasers. By designing two NLP fiber lasers, the distinct autocorrelation trace property for the bound NLPs with a short time interval (around 30 ps), and the high-speed oscilloscope trace characterization for the bound NLPs with a relatively broad time interval (∼500 ps) have all been exhibited. Also, we have demonstrated that it was the Raman effect that mediated the NLP bound states. The experiment results showed that though the inter-interval between the NLPs and the NLP width in the bound states are constantly changing, the envelope of each NLP remained localized and the bound NLPs could maintain within a wide pump range. The dynamics of the experimentally observed bound NLPs have also been discussed with fitting models and numerical simulations. In addition, the experimental test results for the coherence of the NLPs and their bound states further indicated that the NLPs had low temporal coherence characteristics.