Ultrafast Laser Pulses Generation by Using 2D Layered PtS2 as a Saturable Absorber

Platinum disulfide (PtS2) has recently drawn extensive research interest due to its excellent electronic properties, controllable bandgap over a broad range, and high air stability. Herein, we demonstrate the generation of mode-locked ultrafast laser pulses by using PtS2 nanosheets for the first time, which were fabricated by ultrasonic exfoliation followed by the centrifugation process. The fabricated PtS2 saturable absorber (SA) was used within two different fiber laser systems. Ultrafast laser pulses with pulse duration of 2.1 ps, 3-db bandwidth of 2.5 nm, and repetition rate of 15.04 MHz were produced from an Er-doped fiber laser system with an operational wavelength of 1.572 mu m. Additionally, a mode-locking pulse train with repetition rate of 11.2 MHz was obtained by using the fabricated PtS2 SA within Yb-doped fiber laser system with operational wavelength of similar to 1 mu m. It is expected that these results will trigger further research with wide potential applications of PtS2 in the field of nonlinear optics and ultrafast photonics.