From metastable to stable states: Stability and explosion of pure-quartic soliton induced by the spectral filtering in fiber laser

This paper explores the pivotal role of the spectral filtering in pure-quartic soliton (PQS) and its dynamical phenomena in fiber lasers. By incorporating spectral filters, a strategy is introduced to enhance the performance of PQS fiber lasers to produce the transition from metastable PQS state into stable PQS states. Furthermore, by adjusting the negative fourth-order dispersion (FOD) of the cavity and the saturable energy, diverse dynamical behaviors such as the soliton explosion and multi-soliton generation are observed, including the oscillation in pulse energy, soliton splitting, and reconstruction of pulse profile following soliton explosions. The universality of the spectral filtering in stabilizing and controlling multi-soliton states is further validated, which demonstrates that filtered multi-solitons maintain the constant energy over a long-distance transmission while exhibiting the superior stability and robustness against the perturbation. Overall, this study underscores the fundamental role of the spectral filtering in PQS fiber laser, provides a novel experimental platform for investigating soliton dynamics, and significantly contributes to advancing PQS fiber laser technology.