Dynamics of multimode creeping solitons and soliton explosions in a spatiotemporal mode-locked laser.

The study of high-dimensional solitons will bring great interest and new opportunities for understanding three-dimensional nonlinear physical phenomena and the design of complex nonlinear systems. The development of spatiotemporal mode-locked (STML) lasers has enabled the exploration of high-dimensional soliton dynamics. In this study, an STML laser and a dual-channel real-time measurement system based on dispersion Fourier transform technology were constructed. The real-time spectral evolution of high-dimensional solitons, including dissipative solitons, creeping solitons, and soliton explosions, are observed and studied. The experimental results show the complexity of multimode soliton dynamics. Such as multimode solitons possess the spectral-spatial characteristics that are absent in single-mode solitons, the transformations between steady-state solitons, creeping solitons, and soliton explosions, and the relationship between these transformations and pump energy changes and spatiotemporal saturated absorbers. To the best of our knowledge, this is also the first experimental report on multimode creeping solitons. This work provides insight into understanding complex spatiotemporal soliton dynamics and enriches the exploration of, to our knowledge, novel spatiotemporal dynamics.