Enhanced nonlinear optical limiting in TiS2 dichalcogenide 2D Sheets

Two dimensional (2D) graphene and transition metal dichalcogenides are an emerging class of extremely interesting materials showing unique physical properties, such as large third-order optical nonlinearity, offering potential applications in optical limiting. Here we report the optical limiting properties of Titanium disufide (TiS₂), and Graphene sheets measured using open aperture and photo-acoustic z-scan techniques. Our best results were observed in TiS₂ Sheets, yielding an optical limiting of 77% at an irradiance of 0.713 GW/cm²with 2PA and 3PA absorption coefficient to be 80cm/GW and 2000 cm³/GW² respectively.Also, TiS₂ sheets show improved shelf life and stability upon irradiation with higher laser powers. This demonstrates the feasibility of using them as a potential candidate for optical limiting applications.