Fig. 1: Schematic configuration and principle: artificial manipulation on temporal and internal assemblies of soliton molecules.

a An ultrafast laser-based manipulation system, composed of a programmable gain control module, a mode-locking module and a real-time monitoring module. The experimental setup is shown in the inset (see more details in Materials and methods). The nonlinear polarization rotation (NPR) based mode-locking module enables polarization-assisted mode-locking. The cavity repetition rate of the fiber laser resonator is about 54.86 MHz. In addition, the operation wavelength is 1565 nm. DSMs with versatile internal motions are observed by adjusting the intracavity polarization and gain supply. The latter is modulated by electronic control signals, generated from an arbitrary function generator (AFG 31000, Tektronix) with a modulation bandwidth of 25 MHz. In addition, the real-time monitoring of the spectral evolution of dynamic soliton assembly is achieved by real-time spectral interferometry (see more details in Materials and methods). b Conceptual sketch of the artificial manipulation on the soliton assemblies from SS to NP, SP, and PP regimes, actuated by the increased intracavity gain supply. The evolving trajectories of the four phase-defined regimes indicate the ‘none’, ‘negative’, ‘stationary’, ‘positive’ molecular phases, respectively. The temporal assemblies (number of pulses) or internal assemblies (temporal separation τ and molecular phase φ) of DSMs can be deterministically harnessed by the precise gain control