SnS₂ Nanosheets for Er-Doped Fiber Lasers

Stannic sulfide (SnS2), a latterly developed two-dimensional (2D) material, has fascinated scientists because it can be widely applied to materials chemistry, biomedicine, photocatalysis, and so on. Especially, SnS2 has the advantages of adjustable band gap and good oxidation resistance, which indicates that this material has promising potential in nonlinear optics. However, the light interaction with SnS2 is rarely investigated. In this study, high-quality SnS2 nanosheets (Ns) developed through a liquid phase exfoliation approach have been applied in ultrafast photonics for nonlinear processes. This fabrication approach can greatly increase the damage threshold of the SnS2 saturable absorber (SA). Furthermore, the SnS2 SA device is applied to an erbium-doped fiber laser (EDFL) to obtain soliton molecules with different orders. Ultimately, eleventh-order soliton molecules, the highest order of soliton molecules through SnS2, are generated with a soliton separation of 8 ps and a spectral modulation period of around 1 nm. The above experimental results indicate that SnS2 has broad application prospects in the fields of mode-locked fiber laser and optical fiber communication.