Fig. 1. TS-DFT technology. (a) Schematic diagram; (b) time stretch method based on single mode fiber; (c) time stretch method based on chirped Bragg fiber grating

Fig. 2. Single-shot spectral results for soliton and noise-like pulse in PMLFL^[17]. (a) Mean spectrum of soliton; (b) mean spectrum of noise-like pulse; (c) spectrum evolution of soliton; (d) spectrum evolution of noise-like pulse

Fig. 3. Spectrum evolution of soliton explosion^[21].(a) Evolution of single-shot spectrum; (b) spectrum evolution during explosion

Fig. 4. Spectral evolution for the pulsations of single soliton, and a dual-soliton bunch in a PMLFL with self-organized multiple solitons^[26] . (a) Spectrum of single soliton; (b) spectrum of a dual-soliton bunch; (c) single-shot spectra at round trips A and B in Fig.4(a) and averaged spectrum; (d) single-shot spectra at round trips C and D in Fig.4(b) and averaged spectrum

Fig. 5. Spectral sequences for self-started mode-locking process. (a)Single soliton^[32]; (b)soliton molecule^[27]

Fig. 6. Evolution diagrams of spectra and autocorrelation traces during the formation of soliton molecule^[60]. (a) Evolution of spectrum; (b) autocorrelation