本研究發展以史托克參數解出橢偏參數，並以此基礎發展新式的偏振掃描式橢偏儀。我們提出新的參數名為「等效橢偏參數」，不同於傳統式的橢偏參數僅能表示P-S波的關係，它可以表示任意方向的兩個正交波，在經過材料後其相互的振幅及相位關係。模擬結果顯示等效橢偏參數的敏感度在某些特定方向會優於傳統橢偏參數。此橢偏儀由掃描線性偏振光及一道右旋圓偏振光，即可解出所有方向的等效橢偏參數，並以此參數作為基因演算法的目標函數，最後由基因演算法可以解出等向及非等向性光學薄膜的厚度與折射率。此橢偏儀也可應用於TN，VA及ITN的向列型液晶量測，可以解出液晶的厚度，配向與預傾角，另外還可解出TN型液晶的扭轉角。此橢偏儀僅需旋轉偏振片來掃描線性偏振光，量測過程中不需移動量測材料，可以大幅降低機械擾動，並且可應用於生產線上。

A linear-polarized scanning method is proposed for extracting the effective ellipsometric parameters expressed by Stokes parameters explicitly in order to obtain the physical properties of the isotropic thin film, anisotropic thin film, and liquid crystal cell (TN, VA, ITN types). The proposed effective ellipsometric parameters are used to describe the amplitude ratio and phase difference regarding to any two orthogonal waves in arbitrary coordinate instead of the ordinary coordinate for p- and s- waves. Thus, this effective ellipsometric parameter displays the reflectance ratio of two polarizations in arbitrary coordinate. The simulation has shown that some of the effective ellipsometric parameters in some coordinate are more sensitive than the traditional one. The main idea of the proposed scanning ellipsometry is to measure the effective ellipsometric parameters corresponding to all coordinates by scanning the polarization of input light from 0o to 180o plus a right-hand circular light. Following, the Genetic Algorithm (GA) in curve fitting is used to extract the physical properties of the isotropic thin film, anisotropic thin film, and liquid crystal cell from the experimental results. Finally, the experimental values of the effective ellipsometric parameters and the simulated values are compared.
It is shown that for an isotropic thin film, the refractive index and thickness of the isotropic SiO2 film are determined. Also, for an anisotropic thin film, the extraordinary refractive index, ordinary refractive index and thickness of the anisotropic SiO2 film are determined. Meanwhile, for the liquid crystals, the cell gap, pretilt angle, twist angle and rubbing direction of TNLC and the cell gap, pretilt angle and rubbing direction of both VALC and ITNLC can be extracted.
The polarization scanning ellipsometry just simply rotates a polarizer to scan the linear polarization states of incident light without scanning the incident angle and the yaw angle of sample stage. That reduces the mechanical vibration and can be easily applied to the production line.

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