Filtering-induced soliton repelling of dissipative soliton molecules in a mode-locked fiber laser

In mode-locked lasers with filters, the interaction between dissipative soliton molecules (DSMs) is strongly determined by spectral interference and the filter profile, which is a complexity absent in single-pulse dynamics. Here, we experimentally and numerically demonstrate a filtering-induced soliton repelling effect in a Mamyshev oscillator. We show that when the temporal separation of DSMs falls below a critical value, the molecules experience increased filtering loss, leading to a progressive increase in their separation until it stabilizes at a fixed plateau. By varying the intracavity loss, we observe that DSMs adapt their spacing to enhance filter transmittance, thereby maintaining gain-loss balance. Our findings provide a new, to the best of our knowledge, mechanism with which to control multi-pulse regimes in mode-locked lasers.