Fig. 1. Characterization of the few-layer TiS2 nanosheets: (a) TEM image of the TiS2 nanosheets; (b) corresponding Raman spectrum of few-layer TiS2 nanosheets; (c) AFM image of few-layer TiS2 nanosheets; (d) height profile of the section marked in (c).

Fig. 2. (a) Diagram of fabricating the microfiber-based TiS2 using an optical deposition method; (b) saturable absorption property of the SA device.

Fig. 3. (a) Configuration of the Er-doped fiber laser for mode-locking operation; (b) output pulse train; (c) optical spectrum; (d) radio frequency spectra, where fs=22.7  MHz and the higher harmonics on a span of 500 MHz; (e) the intensity autocorrelation profile of the generated pulses.

Fig. 4. (a) Polarization-resolved spectra of the solitons, with a green line and a red line representing the vertical axis and the horizontal axis, respectively; (b) the total and polarization-resolved soliton pulse trains.

Fig. 5. Typical output characteristics of the Q-switched pulses at a pump power of 27.5 mW: (a) optical spectrum; (b) single pulse profile, with a 4.49 μs FWHM pulse width; and (c) radio frequency spectrum of fundamental frequency on a 10 kHz span, where f1=33.387  kHz. (d) Variation of the pulse duration and repetition rate with pump power for the Q-switched Er-doped fiber laser using the few-layer TiS2 SA.