Nonlinear Optical Properties Investigation of Platinum Disulfide (PtS ₂ ) Quantum Dot and its Application in Erbium‐Doped Pulsed Fiber Lasers

Abstract Due to its high carrier mobility, extremely wide light absorption range, and mighty air stability, 2D, platinum disulfide (PtS 2 ) has been widely applied in the field of material science, optoelectronic devices and photocatalysis in recent years. However, the research about PtS 2 quantum dot materials (QDs), especially optical properties, are rarely reported. In this work, PtS 2 QDs are prepared by liquid‐phase exfoliation (LPE), and the nonlinear optical properties of PtS 2 QDs and PtS 2 nanosheets have been investigated by the open aperture (OA) Z‐scan method and the twin‐detectors method, respectively. Furthermore, by mixing PtS 2 QDs with the polyvinyl alcohol (PVA) as saturable absorber, a stable passively Q‐switched Er‐doped fiber laser (EDFL) is achieved. The output laser can be obtained with a repetition rate of 23.04 kHz, pulse width of 21.16 µs, pulse energy of 5.26 nJ, and central wavelength of 1559.97 nm. This suggests that PtS 2 QDs have potential applications in the field of nonlinear optical devices and materials technology.