带有补偿器的液晶相位可变延迟器特性研究

为了能够测量带有补偿器的液晶相位可变延迟器（LCVR）在不同电压值下的相位延迟，提出了一种基于斯托克斯矢量和穆勒矩阵的测量方法。该方法的优点是无需机械旋转、操作简单、测量精度较高。实验测量了可见光范围内6个波长时LCVR在2kHz方波、0-10伏电压值下的相位延迟。实验结果表明，LCVR具有调谐电压低、控制简单、调节范围大、无需转动等优点，相位延迟的测量误差小于0.6%。根据延迟器件的特性，建立了相位延迟的拟合函数公式，采用最小二乘曲线拟合的方法得到了延迟器件工作范围内全部波长、全部电压值下的相位延迟，曲线拟合的标准差小于0.02λ。测量方法、测量结果和拟合函数的建立为偏光器件的研究提供了一定的参考价值。

Study on characteristics of the liquid crystal variable retarder attached with the compensator

In order to measure the retardation of the liquid crystal variable retarder(LCVR) attached with the compensator, a new method is presented in this paper, which is based on Stokes vector and Mueller matrix. This method is simple, precise and no mechanism rotating. A 2 kHz square wave of adjustable amplitude 0-10V is used to control LCVR and the retardation is measured at six wavelengths. The experiment results show that LCVR has the advantages of low voltage controlling, simple operation, wide adjustment range and no need rotating. The error of measurement is less than 0.6%. The fitting function is established based on the characteristics of the retarders. The method of the least-square curve fitting is used to obtain retardation of all wavelengths and all voltages in the working condition of the retarders. The standard error of curve fitting is less than 0.02λ. The measurement method, the experiment results and the fitting function are useful for the polarization device research.