Tripathi Ravi P N, Yang Xiaodong, Gao Jie
Opt Express. 2022 Jun 20;30(13):22661-22670. doi: 10.1364/OE.457858.
Van der Waals (vdW) materials have recently attracted significant interest in the context of orientation-dependent linear and nonlinear optical properties. Recently, arsenic trisulfide (AsS) or orpiment is identified as a new vdW layered material having anisotropic vibrational and optomechanical responses due to the reduced in-plane crystal symmetry, but its nonlinear optical response is still not well understood yet. Herein, the anisotropic third-harmonic generation (THG) response of mechanically exfoliated AsS thin flakes is reported. The polarization-dependent evolution of THG emission from butterfly-shaped pattern to four-lobe pattern is comprehensively explored. Moreover, the third-order nonlinear susceptibility of AsS crystal is extracted by analyzing the thickness-dependent THG emission. We anticipate that the discussed results will not only update the existing understanding on the nonlinear light-matter interaction in anisotropic vdW materials, but also promote future applications in integrated photonic circuits, on-chip nonlinear signal processing, and polarization-sensitive optical devices.
范德华（vdW）材料近来在与取向相关的线性和非线性光学性质方面引起了极大关注。最近，三硫化二砷（AsS）即雌黄被认定为一种新型的范德华层状材料，因其面内晶体对称性降低而具有各向异性的振动和光机械响应，但其非线性光学响应仍未得到充分理解。在此，报道了机械剥离的AsS薄片的各向异性三次谐波产生（THG）响应。全面探究了THG发射从蝶形图案到四叶图案的偏振相关演变。此外，通过分析与厚度相关的THG发射来提取AsS晶体的三阶非线性极化率。我们预计，所讨论的结果不仅会更新对各向异性范德华材料中非线性光与物质相互作用的现有认识，还将推动其在集成光子电路、片上非线性信号处理以及偏振敏感光学器件等方面的未来应用。
