Fig. 1. Schematic setup of the PMLFL and real-time detection system. Two types of dichromatic soliton compounds generated in the PMLFL exhibit different states in both the time domain and frequency domain, as shown in the black dashed line. These two dichromatic soliton compounds periodically collide with each other, leading to complex dynamical processes, as shown in the red dashed box.

Fig. 2. Multichromatic pulse mode-locked state: OSA spectrum at a pump power of 160 mW.

Fig. 3. Experimental observation of multichromatic solitons before and after the TS-DFT process. (a) Real-time direct measurement of spectral evolution over 10,000 round trips. (b) Pulses from the 1000th, 3591st, 4166th, 5000th, 7000th round trips before the TS-DFT process. (c) TS-DFT recording of shot-to-shot spectral evolution over 10,000 round trips. The green curve shows changes in total intracavity pulse energy over these 10,000 round trips; the right insert is an enlarged image of the localized area with weaker CS.

Fig. 4. Structure of FGC. (a) 2D TS-DFT recording of shot-to-shot spectral evolution from the 0th to the 1500th round trip of the FGC. (b) 2D temporal evolution from the 0th to the 1500th round trip of the FGC. (c) Summed intensity of the FGC from the 0th to the 1500th round trip. (d) Energy changes of the DWs and PCDSB within the FGC from the 0th to the 1500th round trip. (e) Energy changes of the DWs and PCDSB within the FGC from the 8000th to the 10,000th round trip.

Fig. 5. Structure of SGC and loosely bound complex. (a) 2D temporal evolution from the 1000th to the 9000th round trip of a single SGC. (b) 2D TS-DFT recording of shot-to-shot spectral evolution from the 1000th to the 9000th round trip of a single SGC. (c) Summed intensity of the SGC before and after the collision; the inset shows the energy changes of the CS and NSP from the 1000th to the 9000th round trip. (d) 2D temporal evolution from the 8000th to the 10,000th round trip of three isolated SGCs and one SGC complex. (e) 2D TS-DFT recording of shot-to-shot spectral evolution from the 8000th to the 10,000th round trip of three isolated SGCs and one SGC complex. (f) Summed intensity of the structures in (e) from the 8000th to the 10,000th round trip.

Fig. 6. Additional TS-DFT recording of shot-to-shot spectral evolution. (a)–(d) Four typical collision evolution processes occurring between two asynchronous compounds are captured.

Fig. 7. Evolution of collision dynamics. (a) 3D shot-to-shot spectral evolution. (b) 2D shot-to-shot spectral evolution from the 1500th to the 6500th round trip of Fig. 3(c).

Fig. 8. Simulation of multi-wavelength pulse propagation in HNLF. (a) Spectra at 0 and 0.7 m propagation distances when the ∼1531.3  nm and ∼1543.2  nm pulses are injected as initial pulse conditions into a 0.7 m HNLF. (b) Spectra at 0 and 0.7 m propagation distances when the four-wavelength pulses are injected as initial pulse conditions into a 0.7 m HNLF when FGC and SGC are in phase. (c) Spectra at 0 and 0.7 m propagation distances when the four-wavelength pulses are injected as initial pulse conditions when SGC is π/4 ahead in phase compared to the FGC. (d) Spectra at 0 and 0.7 m propagation distances when the four-wavelength pulses are injected as initial pulse conditions when SGC is π/2 ahead in phase compared to the FGC.