Backflow-assisted time-resolved phase modulation in nematic liquid crystal Pi-Cells
Backflow-assisted time-resolved phase modulation in nematic liquid crystal Pi-Cells
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DOI：
10.1016/j.optlastec.2022.108596
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Yihan Jin;S. Elston;J. Fells;Bohan Chen;Mengmeng Li;W. Kamal;Zimo Zhao;S. Morris
中科院分区：
文献类型：
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作者：
Yihan Jin;S. Elston;J. Fells;Bohan Chen;Mengmeng Li;W. Kamal;Zimo Zhao;S. Morris
通过监测时间相关的相位调制行为，我们证明了回流的好处的相位调制深度的液晶（LC）的π-细胞相比，观察到的相位调制的其他液晶器件配置。具体而言，结果呈现为时间分辨的相位调制的三种不同的CNOLC设备配置的范围内的电场条件下：π细胞（平行摩擦取向层），Fréedericksz细胞（反平行摩擦取向层），和一个混合对齐的CNOLC（HAN）设备。的时间依赖性的行为实验获得与迈克尔逊干涉仪与压电扫描镜在参考臂，它提供了一个连续的相位斜坡的参考信号。通过记录干涉信号强度，然后可以提取作为时间的函数的光学相位的变化。结果表明，π-电池和Fréedericksz电池都表现出大于π弧度的调制对于双通配置（2π弧度对于四通配置），与π相位调制对应的最低电压幅度被观察到的π-电池。通过时间分辨的响应，它表明，回流的存在阻碍了动态相位响应的Fréedericksz设备，但不会产生负面影响的行为的π细胞。这些结果被发现是在良好的协议与模拟的相位调制的三个反流器件时，考虑回流。
By monitoring the time-dependent phase modulation behavior, we demonstrate the benefits of backflow on the phase modulation depth of nematic liquid crystal (LC) pi-cells in comparison to the phase modulation observed for other nematic LC device configurations. Specifically, results are presented for the time-resolved phase modulation of three different nematic LC device configurations under a range of electric field conditions: pi-cell (parallel-rubbed alignment layers), Fréedericksz cell (anti-parallel rubbed alignment layers), and a hybrid aligned nematic (HAN) device. The time-dependent behavior is obtained experimentally with a Michelson interferometer with a piezoelectric scanning mirror in the reference arm, which provides a continuous phase ramp in the reference signal. By recording the interference signal intensity, it is then possible to extract the change in optical phase as a function of time. It is shown that both the pi-cell and Fréedericksz cell exhibit a modulation that is greater than π radians for a double-pass configuration (2π radians for a four-pass configuration), with the lowest voltage amplitude corresponding to π phase modulation being observed for the pi-cell. Through the time-resolved response, it is shown that the presence of backflow hinders the dynamic phase response of the Fréedericksz device but does not negatively impact the behavior of the pi-cell. These results are found to be in good agreement with simulations of the phase modulation for the three nematic devices when backflow is taken into consideration.