Yu Chih-Jen, Tseng Yao-Teng, Hsu Kuei-Chu, Chou Chien
Graduate Institute of Electro-Optical Engineering, Chang Gung University, Taoyuan 333, Taiwan.
Appl Opt. 2012 Nov 20;51(33):7910-9. doi: 10.1364/AO.51.007910.
In the measurement of a twisted nematic liquid crystal device (TNLCD) by an optical apparatus, the cell parameters of the TNLCD may result in multiple solutions in the measurement that all agree with the measured data; hence manufacturers cannot find a set of correct solutions from among the ambiguous ones. With the help of the optical equivalence theorem of a unitary optical system, the ambiguity of the measured parameters of a TNLCD, including cell parameters and equivalent birefringent parameters, can be simultaneously removed by an analytical approach using a single-wavelength polarimeter. The procedure for unique determination of the cell parameters is performed using a self-consistent condition to select a set of the correct solutions from all the possible solutions. The proposed method can be applied to characterize a generally TNLCD for which the twisted angle is close to 270° and the liquid crystal phase retardation is over 2π.
在通过光学仪器测量扭曲向列型液晶器件（TNLCD）时，TNLCD的盒参数可能会导致测量中出现多个都与测量数据相符的解；因此，制造商无法从这些模糊的解中找到一组正确的解。借助幺正光学系统的光学等效定理，利用单波长偏振计通过解析方法可以同时消除TNLCD测量参数（包括盒参数和等效双折射参数）的模糊性。使用自洽条件从所有可能的解中选择一组正确的解，来执行唯一确定盒参数的过程。所提出的方法可应用于表征扭曲角接近270°且液晶相位延迟超过2π的一般TNLCD。
