Ternary Chalcogenide Ta₂NiTe₅ as Broadband Saturable Absorber for Passively Q‐Switched Pulse Generation

Abstract Two dimensional (2D) ternary chalcogenides, a significant class of optoelectronic materials, exhibit distinctive structures and possess exceptional physical and chemical properties. In this study, a novel 2D ternary chalcogenide, Ta₂NiTe₅, is synthesized using the liquid‐phase exfoliation technique to create a high‐quality saturable absorber (SA). The nonlinear optical characteristics of the prepared Ta₂NiTe₅ nanosheets, ranging from 500 nm to 3.0 µm, are investigated using the P‐scan and open‐aperture Z‐scan methods. Furthermore, the stable passively Q‐switched lasers based on the Ta₂NiTe₅‐SA device are realized with a minimum pulse width of 326 ns, 2.18 µs, and 850 ns at 1.0, 2.0, and 3.0 µm wavelengths, respectively. The findings not only provide further evidence of the promising potential of 2D ternary chalcogenides as an SA for the achievement of broadband pulsed lasers, but also pave the way for promoting their potential applications in optoelectronic devices.