Measuring the spatial distribution of liquid crystal alignment and retardation using stokes polarimetry
Measuring the spatial distribution of liquid crystal alignment and retardation using stokes polarimetry
复制标题
使用斯托克斯偏振法测量液晶排列和延迟的空间分布
DOI：
10.1117/12.2552931
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
H. Zappe
中科院分区：
文献类型：
--
作者：
Y. Folwill;H. Zappe
我们提出了一种方法来确定二维空间分布的取向以及延迟的一个双折射液晶层。最近开发的用于液晶的新颖对准技术使得能够定义任意空间对准图案，其然后可以用于成形用于诸如q板或衍射光学元件的应用的光束。为了量化取向质量，在大的二维区域上以高空间分辨率确定液晶主轴（在0°和180°之间）的取向的测量方法是必不可少的。我们的方法是基于测量光通过液晶薄膜时发生的偏振变化。然后，我们展示了一种方法来推导出的取向方向和延迟的薄膜从偏振的变化。为了证明这种方法的能力，我们测量了难以用其他方法明确量化的特定对齐模式。
We present a method to determine the two-dimensional spatial distribution of alignment as well as retardation of a nematic liquid crystal layer. Recently-developed novel alignment techniques for liquid crystals enable the definition of arbitrary spatial alignment patterns, which can then be used to shape optical beams for applications such as q-plates or diffractive optical elements. In order to quantify the alignment quality, a measurement method to determine the alignment of the major axis of the liquid crystals (between 0° and 180° ) with high spatial resolution over a large two-dimensional area is essential. Our approach is based on measuring the change in polarization of light that occurs on passing through a liquid crystal film. We then show a method to deduce the alignment direction and the retardation of the film from the change in polarization. To demonstrate the capabilities of this method, we measure specific alignment patterns that are difficult to quantify unambiguously with other methods.