Nowadays, realizing miniaturized nonlinear optical (NLO) device is crucial to meet the growing needs in on-chip nanophotonics as well as compact integrated devices. The strong optical nonlinearities, ultrafast photoexcitation dynamics, available exciton effects as well as without lattice matching make two-dimensional (2D) layered materials potential candidates for integrated and nano-scale NLO devices. Herein, a novel and inversion symmetry broken 2D layered SnP₂S₆ with strong second-harmonic and third-harmonic response has been reported for the first time. The second-order susceptibility (χ⁽²⁾) of SnP₂S₆ flakes can reach up to 4.06 × 10⁻⁹ m·V⁻¹ under 810 nm excitation wavelength, which is around 1–2 orders of magnitude higher than that of most reported 2D materials. In addition, the NLO response of 2D SnP₂S₆ can break through the limitation of odd/even layers and exhibit broadband spectral response. Moreover, since the second-harmonic signal is closely related to structure variation, the second-harmonic response in 2D SnP₂S₆ is extremely sensitive to polarization angle and temperature, which is beneficial to some specific applications. The excellent NLO response in 2D SnP₂S₆ provides a new arena for realizing miniaturized NLO devices in the future.

如今，实现小型化非线性光学 (NLO) 器件对于满足片上纳米光子学以及紧凑型集成器件不断增长的需求至关重要。强光学非线性、超快光激发动力学、可用激子效应以及没有晶格匹配使二维 (2D) 层状材料成为集成和纳米级 NLO 器件的潜在候选者。在此，首次报道了一种具有强二次谐波和三次谐波响应的新颖且反演对称性破缺的二维分层 SnP ₂ S ₆。SnP ₂ S ₆薄片的二阶磁化率( χ ⁽²⁾ )可以达到4.06 × 10 ^-9 m·V ^-1在 810 nm 激发波长下，这比大多数报道的二维材料高约 1-2 个数量级。此外，2D SnP ₂ S ₆的非线性光学响应可以突破奇/偶层的限制，表现出宽带光谱响应。此外，由于二次谐波信号与结构变化密切相关，2D SnP ₂ S _{6 中}的二次谐波响应对偏振角和温度极为敏感，这有利于某些特定应用。2D SnP ₂ S _{6 中}出色的 NLO 响应为未来实现小型化 NLO 设备提供了新的领域。