Bankova Denitsa, Podoliak Nina, Kaczmarek Malgosia, D'Alessandro Giampaolo
School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ, UK.
School of Mathematical Sciences, University of Southampton, Southampton, SO17 1BJ, UK.
Sci Rep. 2024 Jul 31;14(1):17713. doi: 10.1038/s41598-024-68812-x.
We present a reliable optical method for measuring the twist elastic constant and for assessing the total twist angle in a standard nematic twist cell. The method relies on the use of a non-standard configuration of crossed polarisers and a twist cell, which allows us to measure accurately the twist-cell parameters by reducing the degeneracy between them. Grid patching and an efficient beam propagation method are utilised in the numerical models used for fitting the experimental data. The modelling shows that the polarisation dynamics in a twist cell is non-trivial and much more complex than in a planar cell. The twist elastic constant of three commonly used liquid crystals (5CB, 6CHBT and E7) was successfully extracted from cross-polarised intensity measurements.
我们提出了一种可靠的光学方法，用于测量标准向列型扭曲盒中的扭曲弹性常数并评估总扭曲角。该方法依赖于使用交叉偏振器和扭曲盒的非标准配置，这使我们能够通过减少它们之间的简并性来准确测量扭曲盒参数。在用于拟合实验数据的数值模型中采用了网格修补和高效光束传播方法。建模表明，扭曲盒中的偏振动力学并非简单，且比平面盒中的要复杂得多。从交叉偏振强度测量中成功提取了三种常用液晶（5CB、6CHBT和E7）的扭曲弹性常数。
