本篇中利用偏振干涉儀的原理，設計了一個架構可以間接量測到薄膜的反射係數，進一步求得薄膜的光學導納值。在單層膜且不考慮吸收膜的情況下，我們可以直接經由計算得到膜的折射率以及厚度，而在多層膜的情況下，則需要利用數值方法擬合（fitting）出各層薄膜的折射率以及厚度。 實驗架構上以Twyman-Green干涉儀的兩臂來產生兩道偏振態互相垂直的光，再以Fizeau干涉儀的概念產生干涉作用，整體簡單易架設並且可以迅速得到結果。 本文中將以數學以及實驗驗證上述特性，其中實驗驗證方面分別包括第一部分的實驗架構及討論以及第二部份改良過後的實驗架構及結果。A new method based on polarization interferometry is demonstrated. An optical system is built to obtain the phase and magnitude of reflection coefficient, as well as the optical admittance at normal incidence. We use Twyman Green interferometer to induce phase difference between two beams which have orthogonal polarizations and the Fizeau cavity makes interference happen. The refractive index and thickness of single layer thin film can be analytically found without numerical fitting. In addition,, we can use numerical fitting to get the refractive and index, thickness for multilayer film stack. In this article, the validity of the above characteristics will be examined theoretically and experimentally. There are two parts in this study. The first part of the experiments is the framework and discussion and the second part is the second kind of framework and experimental results.
