Zinc oxide (ZnO), as one of the third-generation semiconductor materials, has attracted extensive research interest, but its nonlinear optical properties in near-infrared (NIR) band are rarely involved. Herein, the beam propagation diffraction model has been extended to handle up to the 9th-order optical nonlinearity, and still has excellent performance of fitting experimental data. Multiphoton absorption effects were experimentally investigated by z-scan measurement in visible (VIS)-NIR bands. In an N-photon absorption (N-PA) spectral regime, the respective N-PA effect dominates nonlinear absorption, while all other orders are negligible under the experimental laser intensities. In VIS-NIR bands, only the third-order nonlinear refraction is significant for Kerr nonlinear refractive index, while the higher orders can be ignored. The nonlinear figure of merit is low due to the strong 2PA effect in VIS band, but increases by an order of magnitude, up to a maximum value of 5.8, in the spectral region where the 2PA effect diminishes. These results indicate that ZnO is a valuable candidate for nonlinear photonics applications in a broad NIR band accommodating telecom wavelength.

氧化锌（ZnO）作为第三代半导体材料之一，引起了广泛的研究兴趣，但其在近红外（NIR）波段的非线性光学特性却鲜有涉及。在这里，光束传播衍射模型已经扩展到可以处理高达 9 阶的光学非线性，并且仍然具有很好的拟合实验数据的性能。通过在可见光 (VIS)-NIR 波段中的z扫描测量，对多光子吸收效应进行了实验研究。在N-光子吸收 ( N- PA) 光谱范围内，相应的N-PA 效应主导非线性吸收，而所有其他阶次在实验激光强度下都可以忽略不计。在 VIS-NIR 波段，只有三阶非线性折射对克尔非线性折射率显着，而更高阶的可以忽略不计。由于 VIS 波段中的 2PA 效应强，非线性品质因数较低，但在 2PA 效应减弱的光谱区域中，非线性品质因数增加一个数量级，最高可达 5.8。这些结果表明，ZnO 是适用于电信波长的宽 NIR 波段非线性光子学应用的宝贵候选材料。