Inkjet-printed tunable 2D metal thiophosphate saturable absorbers for pulsed solid-state laser applications

Abstract

Saturable absorbers (SAs) based on novel two-dimensional (2D) materials have gained significant attention for their favorable processing characteristics, desirable structures, and excellent nonlinear optical properties, particularly in solid-state laser pulse generation. However, developing a tunable 2D material-based SA device that offers both high stability and superior performance remains challenging. In this study, we synthesized 2D lamellar metal thiophosphates (NiPSe3, CoPS3, and CrPSe4) using the liquid-phase exfoliation method and fabricated SA devices through inkjet printing technology. We systematically investigated the nonlinear optical responses of the NiPSe3, CoPS3, and CrPSe4 nanosheets (NSs) at 1 μm, revealing distinct modulation capabilities for different pulsed laser applications. The NiPSe3, CoPS3, and CrPSe4 NSs were subsequently employed as SAs in various pulsed solid-state lasers, including a continuous wave pumping passively Q-switched (PQS) laser, a pulse-pumping PQS laser, and a Q-switched mode-locking laser. Our findings not only highlight viable SA options for solid-state pulsed lasers but also pave the way for expanding the applications of the 2D lamellar metal thiophosphates family in nonlinear optics.