光彈調變式橢圓偏光儀對扭轉式液晶盒的量測

Abstract

本論文以橢圓偏極術為基礎，在不需轉動樣本方位角的情況下，以不同偏振方向的線性偏振光入射樣本，藉由出射光偏振態的變化，用數值方法擬合出樣本矩陣模型參數；我們所量測的樣本為扭轉式液晶盒，其矩陣模型包含了三個參數：總相位延遲、扭轉角及第一層液晶錨定方向。根據我們的量測結果，標準差最大為 ，將量測結果和一般常見的量測方法結果做比較，結果相當一致。此外我們還從實驗數據中，驗證了符合偏振追隨 (Adiabatic Following) 之液晶盒矩陣模型與旋轉矩陣的關係。最後，我們提出一個光偏振態的即時量測方法，可即時觀察光偏振態在邦加球上的變化。

This ellipsometric method does not need to rotate the sample azimuthally. The physical parameters of sample are measured under various linear polarized lights through the numerical fitting to its theoretical model. In addition to the orientation of the first layer of nematic liquid crystal is considered, the total phase retardation and twist angle of twist Nematic Liquid Crystal cell are the physical parameters measured by this method. In our error analysis: the maximum error of these three parameters is . By comparison, our results agree well with that measured by the conventional method of A. Lien. The adiabatic following model is closely analyzed. In our measurements, the condition of adiabatic following model is demonstrated. In the end, we also propose a technique to trace out the polarization state on Poincare sphere in real time.