Alignment structures and diffraction properties of chiral nematic liquid crystal cells with periodically patterned photoalignment films
Alignment structures and diffraction properties of chiral nematic liquid crystal cells with periodically patterned photoalignment films
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DOI：
10.7567/jjap.55.012001
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发表时间：
2015
影响因子：
1.5
通讯作者：
T. Sasaki;Reijiro Shimura;Kotaro Kawai;Kohei Noda;M. Sakamoto;N. Kawatsuki;H. Ono
中科院分区：
文献类型：
--
作者：
T. Sasaki;Reijiro Shimura;Kotaro Kawai;Kohei Noda;M. Sakamoto;N. Kawatsuki;H. Ono
使用手性向列液晶 (N*LC) 制造具有周期性排列分布的液晶 (LC) 单元，该液晶单元是使用向列液晶和手性掺杂剂的混合物以及光反应性液晶聚合物 (PLCP) 薄膜制备的。通过偏振全息记录在 PLCP 薄膜中形成周期性结构。每个单元中的指向矢分布取决于手性掺杂剂存在的比例，即 N*LC 的固有螺距。基于N*LC的弹性连续介质理论和PLCP薄膜的光配向效应，很好地解释了LC光栅单元中这些具有线缺陷的周期性配向结构。还使用偏振可见激光研究了光栅液晶盒的衍射特性。观察到的衍射光束的强度和偏振状态与使用指向矢分布模型计算的理论值一致。我们的结果表明，光栅液晶盒的衍射特性可以通过 N*LC 的螺距控制。
Liquid crystal (LC) cells with periodic alignment distributions were fabricated using chiral nematic LCs (N*LCs), which were prepared using mixtures of a nematic LC and a chiral dopant, along with photoreactive liquid crystalline polymer (PLCP) films. Periodic structures were formed by polarization holographic recording in the PLCP films. The director distribution in each cell depended on the ratio of chiral dopant present, i.e., the inherent helical pitch of the N*LCs. These periodic alignment structures with line defects in the LC grating cells were well explained on the basis of the elastic continuum theory of the N*LCs and the photoalignment effect of the PLCP films. The diffraction properties of the grating LC cells were also investigated using a polarized visible laser. The observed intensity and polarization states of the diffracted beams were consistent with theoretical ones calculated using the director distribution models. Our results clarify that the diffraction properties of the grating LC cells can be controlled by the helical pitch of the N*LCs.