Fig. 1. Characterization of few-layer MoSe2 by the LPE method. (a) MoSe2 solution before (left) and after (right) sonication. (b) XRD patterns of the bulk MoSe2 (top) and exfoliated few-layer MoSe2 (bottom). (c) Typical AFM image and the height profile diagram (inset) of the few-layer MoSe2 nanosheets. (d) Raman spectrum of the exfoliated MoSe2.

Fig. 2. Balanced twin-detector measurement system for measuring the NLO absorption of the fiber-compatible PVA-MoSe2 film.

Fig. 3. Measured nonlinear absorption characteristics of the few-layer MoSe2 film at 1566 nm wavelength. SA, saturable absorption.

Fig. 4. Experiment setup of the proposed EDFL passively mode-locked by the few-layer MoSe2 film.

Fig. 5. (a) Optical spectrum and (b) typical oscilloscope trace of the passive Q-switching operation at the pump power of 17.4 mW. Inset, single-pulse envelope.

Fig. 6. (a) Mode-locked optical spectrum and (b) mode-locked pulse trains at the pump power of 33.4 mW.

Fig. 7. (a) RF spectrum of the mode-locked pulses at the fundamental RF peak. (b) Broadband RF spectrum with a frequency span of 600 MHz. The autocorrelation traces of the mode-locked pulses with the (c) narrow and (d) broad scanning range are also shown.

Fig. 8. Average output power as a function of the pump power when (a) turning on and (b) turning off the pump power.

Fig. 9. Stability measurement of soliton mode locking by repeatedly scanning the output optical spectra at 10-min intervals.