用偏光干涉法动态测量扭曲向列型液晶指向矢

Polarization Interference Method for Dynamic Measurement of Twisted Nematic Liquid Crystal Director

提出一种基于双折射晶体劈的偏振态实时测量方法,并将该方法用于扭曲向列型液晶透射光的偏振态分析,实现了液晶分子平均指向矢的动态测量.利用基于晶体劈的偏光干涉法将待测光的偏振参量编码为两组干涉条纹,通过对干涉条纹定位实现偏振态的实时测量;再根据液晶指向矢的倾角、扭转角与透射光偏振态之间的关系,推算出液晶分子平均指向矢的动态信息.本实验测量液晶指向矢的速度为每秒5次,液晶平均指向矢的倾角、扭转角的测量准确度达到0.2°.本文研究为液晶分子平均指向矢的动态测量提供了一种有效途径.

A real-time method for measuring the polarization state based on birefringence crystal wedge was proposed and it was applied to analyze the polarization state of transmitted light from twist nematic liquid crystal, the dynamic measurement of liquid crystal molecule mean director was achieved by this method. Polarization interference method based on crystal wedge was used to encode the polarization parameters of detected light into two groups of interference fringes, real-time measurement of polarization state was realized through stripe position location. According to the relationship between the director angle of liquid crystal director and transmitted polarization state, dynamic information of liquid crystal mean director can be derived. The measurement speed is 5 time per second in this experiment, and the accuracy of tilt and twist angle of liquid crystal average director is 0. 2 degree. An effective and valuable approach for rapid measurement of liquid crystal molecule mean director is provided in this work.