Fig. 1. Schematic diagram of the mode-locked Nd:LuVO4 laser using PtSe2 film as the saturable absorber.

Fig. 2. (a) XRD pattern of the as-prepared PtSe2 film; inset, enlarged part of the original XRD pattern of the PtSe2 film; (b) Raman spectrum of PtSe2; inset, Raman mapping image of PtSe2 film obtained within an area of 10  μm×10  μm; (c) AFM image of PtSe2 film; (d) cross-section height profile of PtSe2 film obtained from AFM image.

Fig. 3. (a) Photograph of PtSe2 film on quartz substrate with a size of 1.5  cm×1.5  cm. (b), (c) TEM images of PtSe2 film with different magnifications; (d) HRTEM image of the PtSe2 film; (e) SAED pattern; (f) EDS spectrum of the PtSe2 film.

Fig. 4. (a) Nonlinear optical transmittance curve of the PtSe2 film; (b)–(d) typical mode-locked pulse trains recorded on different time scales of the mode-locked solid-state laser using PtSe2 film as a saturable absorber.

Fig. 5. (a), (b) Output spectra of the solid state before and after mode locking, respectively; (c) average output power versus incident pump power.