This study deals with numerical simulations to optimize the parameters of the Dark Filed Z-scan (DFZ-scan) in a microscopic configuration for third-order nonlinear (NL) refraction measurements into thin films. The method allows dynamic, transparent, nonlinear phase shifts to be clearly visible. The simulations of such images are obtained for very low-induced refractive indices. Darkfield illumination requires blocking out of the central light which ordinarily passes through and around (surrounding) the NL specimen. A table to approximate circular aperture stop size versus magnification will be given depending on the focusing lens into the tested material.

中文翻译：

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用于非线性光学测量的暗场 Z 扫描显微结构：数值研究

本研究涉及数值模拟，以优化薄膜中三阶非线性 (NL) 折射测量的微观配置中的暗场 Z 扫描 (DFZ-扫描) 的参数。该方法允许动态的、透明的、非线性的相移清晰可见。此类图像的模拟是针对非常低的诱导折射率获得的。暗场照明需要阻挡通常穿过和环绕（环绕）NL 样本的中心光。根据测试材料中的聚焦透镜，将给出一个近似圆形孔径光阑尺寸与放大率的表格。