In this paper, we demonstrate a novel optical characterization method for ultrathin semitransparent and absorbing materials through multispectral intensity and phase imaging. The method is based on a lateral-shearing interferometric microscopy (LIM) technique, where phase-shifting allows extraction of both the intensity and the phase of transmitted optical fields. To demonstrate the performance in characterizing semitransparent thin films, we fabricated and measured cupric oxide (CuO) seeded gold ultrathin metal films (UTMFs) with mass-equivalent thicknesses from 2 to 27 nm on fused silica substrates. The optical properties were modeled using multilayer thin film interference and a parametric model of their complex refractive indices. The UTMF samples were imaged in the spectral range from 475 to 750 nm using the proposed LIM technique, and the model parameters were fitted to the measured data in order to determine the respective complex refractive indices for varying thicknesses. Overall, by using the combined intensity and phase not only for imaging and quality control but also for determining the material properties, such as complex refractive indices, this technique demonstrates a high potential for the characterization of the optical properties, of (semi-) transparent thin films.

中文翻译：

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半透明超薄膜的多光谱全息强度和相位成像

在本文中，我们通过多光谱强度和相位成像展示了一种用于超薄半透明和吸收材料的新型光学表征方法。该方法基于横向剪切干涉显微镜 (LIM) 技术，其中相移可以提取透射光场的强度和相位。为了展示表征半透明薄膜的性能，我们在熔融石英基底上制造并测量了质量当量厚度为 2 至 27 nm 的氧化铜 (CuO) 晶种金超薄金属薄膜 (UTMF)。使用多层薄膜干涉及其复折射率的参数模型对光学特性进行建模。使用所提出的 LIM 技术对 UTMF 样品在 475 至 750 nm 的光谱范围内进行成像，并将模型参数拟合到测量数据，以确定不同厚度的相应复折射率。总体而言，通过使用组合的强度和相位，不仅用于成像和质量控制，而且还用于确定材料特性，例如复折射率，该技术展示了表征（半）透明材料的光学特性的巨大潜力。薄膜。