Opt Lett. 2019 Nov 1;44(21):5214-5217. doi: 10.1364/OL.44.005214.
We report on an unambiguous observation of the third-order nonlinear optical effect, spatial self-phase modulation (SSPM), in a MoTe dispersion. The values of the third-order nonlinear optical coefficients effectively for one-layer MoTe, χone-layer(3), are obtained through the SSPM method at excitation wavelengths 473, 532, 750, and 801 nm, respectively. The wind-chime model is used to explain the ring formation time. The wavelength dependence of χone-layer(3) compares well with the photo-absorption spectra. Significantly, we find a correlation between χ and the carrier mobility μ or effective mass m*, which again further supports the laser-induced ac electron coherence in 2D materials.
我们报告了在 MoTe 分散体中三阶非线性光学效应，即空间自相位调制（SSPM）的明确观察结果。通过 SSPM 方法，在激发波长 473、532、750 和 801nm 处，分别获得了单层 MoTe 的三阶非线性光学系数χone-layer(3)的值。风铃声模型用于解释环形成时间。χone-layer(3)的波长依赖性与光吸收光谱很好地吻合。值得注意的是，我们发现 χ 与载流子迁移率 μ 或有效质量 m*之间存在相关性，这再次进一步支持了二维材料中的激光诱导 ac 电子相干性。
