Unveiling manipulation mechanism on internal dynamics of soliton triplets via polarization and gain control

Self-assembly of ultrashort pulses highlights the complex patterns of dissipative solitons, termed soliton molecules in consideration of the particle-like behaviors. Multi-constituent temporal patterns release the degrees of freedom of versatile internal motions, emphasizing the molecular-analogous soliton dynamics and the advanced laser ap-plications. Beyond previous studies, exploring the artificial manipulation of the intra-molecular dynamics would spread a new research horizon of ultrafast science. Here, we report the research on the manipulation mechanism on the internal dynamics under a tri-soliton model via the implementation of the polarization and gain control. Assisted with real-time spectral interferometry, both the binding separations and the relative phases are retrieved to unfold the intra-molecular dynamics of soliton triplets. Particularly, we present the switching among tri-soliton states identified by different binding separations and phase-evolving velocities, and further unveil the universal rules of the internal dynamics. All these findings provide an evident manifestation of the artificial manipula-tion on the temporal distributions and intra-molecular dynamics, as well as enable promising access to rapid multi-pulse reconfiguration applicable to fiber laser platforms.