Noise-like dissipative soliton molecules in a normal dispersion fiber laser

Phenomena associated with multi-pulse structures have significantly expanded the exploration of ultrashort pulse dynamics beyond conventional single-pulse regimes in passively mode-locked fiber lasers. In this study, we investigate the characteristics and evolution mechanisms of a series of specially structured dissipative soliton molecules (DSMs). Through precise adjustment of polarization controllers under optimized pump power conditions, we observed a distinct transition from typical DSMs to structured noise-like soliton molecules. Subsequent numerical simulations not only replicated the experimental observations but also provided an in-depth analysis of the underlying dynamics. These findings enhance our understanding of soliton dynamics in fiber lasers operating under normal dispersion conditions and offer critical insights into the manipulation of multi-soliton systems involving noise-like pulses and complex soliton structures.