Fig. 1. Schematic diagram of the experimental setup. EDF, erbium-doped fiber; PC, polarization controller; LD, laser diode; SA, saturable absorber; WDM, wavelength-division-multiplexed coupler; PI-ISO, polarization-independent isolator; OSA, optical spectrum analyzer; DCF, dispersion compensation fiber.

Fig. 2. Real-time observation of starting (left) and shutting (right) processes for (a) CSs, (b) SPs, and (c) DSs. These are the detection results of the oscilloscope after transmission in DCF. The relative coordinates are used for time and intensity.

Fig. 3. Shutting process of CSs when the turn-off time is more than 5 ms. This is the direct measuring result without DFT.

Fig. 4. Starting and shutting dynamics for the CS fiber laser. (a) Real-time spectral evolution dynamics during the formation of CSs. (b) Real-time spectral evolution dynamics during the shutting for CSs. (i) and (ii) show the energy evolution corresponding to (a) and (b), respectively. (c) Optical spectra of solitons measured by the OSA and DFT technique. (d) Close-up of the data in the square of (a), revealing the interference pattern for the beating dynamics and the complex multi-pulse evolution. (e) Fourier transform of each single-shot spectrum corresponds to the field autocorrelation of (d). RT: roundtrip.

Fig. 5. Starting and shutting dynamics for the SP fiber laser. (a) Real-time spectral evolution dynamics during the formation of SPs. (b) Real-time spectral evolution dynamics during the shutting process for SPs. (i) and (ii) show the energy evolution corresponding to (a) and (b), respectively. Experimental real-time observation without DFT for the (c) starting and (d) shutting processes, corresponding to (a) and (b), respectively. Results with and without DFT display a time difference due to the delay of DCF. (e) Close-up of the data from region A in (a), revealing the interference pattern for the beating dynamics. (f) Interaction of SPs and picosecond pulses. The data are from region B in (a). (g) Optical spectra of SPs measured by the OSA and DFT technique.

Fig. 6. Interaction of SPs and picosecond pulses. Data are from Fig. 5(f).

Fig. 7. Starting and shutting dynamics for the DS fiber laser. (a) Real-time spectral evolution dynamics during the starting of DSs. (b) Real-time spectral evolution dynamics during the shutting for DSs. (i) and (ii) show the energy evolution corresponding to (a) and (b), respectively. Experimental real-time observations without DFT for the (c) starting and (d) shutting processes correspond to (a) and (b), respectively. (e) Spectral evolution for the formation of DSs. The data are extracted from the square region in (a). (f) Optical spectra of DSs measured by the OSA and DFT technique.