The present paper concerns the oxide layer thickness determination of oxidized metals in the case where an optical interference phenomenon occurs due to multiple reflections inside the oxide layer. The paper focuses on anodized titanium but can be extended to the layer thickness determination of any material composed of a non-absorbing layer over an absorbing substrate. It establishes theoretical formulae to compute the oxide layer thickness from the positions of the local extrema of the material reflectance spectra. In contrast with many publications these formulae take into account the air/oxide and oxide/metal interfaces’ electromagnetic phase-shift. They make also the distinction between TE-, TM- and non-polarized light and are valid for all incidence angles. By applying these formulae to simulated reflectance spectra with known oxide thicknesses, we show that neglecting the interface phase-shift is not appropriate for determining the oxide thickness of samples with thin oxi...

中文翻译：

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从反射光谱的极值确定氧化金属的氧化物层厚度：理论基础及其在阳极氧化钛中的应用

本发明涉及在由于氧化物层内部的多次反射而发生光干涉现象的情况下对氧化金属的氧化物层厚度的确定。本文着重于阳极氧化钛，但可以扩展到确定由吸收性基材上的非吸收层组成的任何材料的层厚度。它建立了从材料反射光谱的局部极值位置计算氧化物层厚度的理论公式。与许多出版物相反，这些公式考虑了空气/氧化物和氧化物/金属界面的电磁相移。它们还可以区分TE，TM和非偏振光，并且对所有入射角均有效。