Femtosecond ultrafast pulse generation with high-quality 2H-TaS2 nanosheets via top-down empirical approach

Tantalum disulfide (TaS2), an emerging group VB transition metal dichalcogenide, with unique layered structure, rich phase diagrams, semimetallic behavior, higher carrier concentration and mobility is emerging as a prototype for revealing basic physical phenomena and developing practical applications. While, its photonics properties and even engineering-related processes are still rare. Here, the top-down experiment demonstration including synthesis, thickness optimization and nonlinear optical application were reported. In addition, the ultrafast (~373 fs) erbium-doped fiber pulse with a small time-bandwidth product (~0.34) and long-term stability (~25 days) was realized by using nonlinear absorption properties of the high-quality 2H-TaS2 nanosheet. These results suggests a experimental route for further ultrafast photonics explore based on metallic transition metal dichalcogenides.