石英式補波片旋光性之影響

Abstract

我們以亮比式的觀念，發展了一套操作過程簡單，且重覆性高的穿透式 偏極光儀之量測技術－測量補波片的相位延遲、旋光性及光軸位置。實驗 時利用 PA (Polarizer-Analyzer) 系統中之析光角為 0,60,120 度所測 得的三組亮度可校正偏光角 P ，再利用 PCA (Polarizer-Compensator- Analyzer) 系統以偏光角為 P 與 P+45 度，分別取得析光角仍為 0,60,120 度的六組亮度值。同時計算出石英 (Quartz) 及雲母 (Mica) 補波片方位角 C、相位延遲及橢圓傾角ε之值。 如此補波片材料所具有 的相位延遲 ，將被獨立成兩部份:包含旋光性的相位延遲ρ 及因雙折射 性質而產生的相位延遲δ，進而推算出四分之一波長之石英式補波片的旋 光參數G 。 By intensity radio technique, we develop an easy way to measure polarmetric parameters, since it is useful to measure the optical axis, phase retardation and ellipticity angle of a quarter waveplate. We proved that only by three intensity measurements in a PA (Polarizer-Analyzer) system, and other six intensity measurements in a PCA (Polarizer-Compensator-Analy) system, one can calculate the azimuth angle, phase retardation and ellipticity angle of any waveplate. We evaluated the phase retardation of quartz and mica quarter waveplate by this technique. We found the phase retardation of quartz quarter waveplate caused by both optical activity and birefringence of the material. In advance, we can also find the gyration parameters of the quarez quarter waveplate.