Two-dimensional (2D) heterostructure materials have attracted increasing attention in ultrafast nonlinear optical applications due to their intriguing properties. Here, we fabricate a graphene/α-In2Se3 heterostructure by dropping α-In2Se3 dispersion onto the surface of few-layered graphene film and investigate its nonlinear optical responses. We show that the graphene/α-In2Se3 heterostructure has combined advantages of ultrafast relaxation (τ1 ∼ 78 fs, τ2 ∼ 14 ps) and a large effective nonlinear absorption coefficient (βeff ∼ −1.2 × 104 cm/GW) with relatively large modulation depth. We have further integrated the heterostructure into an erbium-doped fiber laser for mode-locked pulse generation. These results indicate that graphene/α-In2Se3 heterostructures are a promising 2D material for ultrafast nonlinear optical applications.

中文翻译：

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用于超快非线性光学应用的石墨烯/α-In2Se3 异质结构

二维 (2D) 异质结构材料由于其有趣的特性，在超快非线性光学应用中引起了越来越多的关注。在这里，我们通过将 α-In2Se3 分散体滴到几层石墨烯薄膜的表面上来制造石墨烯/α-In2Se3 异质结构，并研究其非线性光学响应。我们表明石墨烯/α-In2Se3 异质结构结合了超快弛豫（τ1 ∼ 78 fs, τ2 ∼ 14 ps）和较大的有效非线性吸收系数（βeff ∼ -1.2 × 104 cm/GW）和相对较大的调制深度的优点. 我们进一步将异质结构集成到掺铒光纤激光器中，用于产生锁模脉冲。这些结果表明石墨烯/α-In2Se3 异质结构是一种用于超快非线性光学应用的有前途的二维材料。