Nonlinear optical response of ternary chalcogenide nanoflakes for the pulse generation near 2 μm

Abstract Ternary chalcogenides possess a promising prospect for their superior nonlinear optical response, offering new opportunities in future photonic devices. Ta2NiS5 and Ta2NiSe5 nanoflakes fabricated by liquid-phase exfoliation were investigated. Based on Tm:YAG ceramic and Tm,Ho:Ca(Gd,Lu)AlO4 crystal as gain media, the doubly passively Q-switched lasers with Ta2NiS5 and Ta2NiSe5 saturable absorbers were realized. The shortest pulse duration was 391 ns, which was realized in Tm,Ho:Ca(Gd,Lu)AlO4 laser. And the highest peak power 17.73 W was obtained in Tm:YAG ceramic laser. The results demonstrate that the Ta2NiS5 and Ta2NiSe5 nanomaterials have the potential to generate a short-pulsed laser. Doubly Q-switching technology can compress pulse duration and enhance peak power.