Research Development for Liquid-Crystal Optical-Wavefront-Control-Devices by using Molecular Orientation Effects

1.我们制作的液晶盒是使用一个双折射液晶和基板上的光刻部分图案化的平行取向层上的聚酰亚胺（PI）垂直取向层，其中液晶分子部分排列平行和垂直于基板，分别.测量了平行取向层和垂直取向层边界区域的光学延迟特性，解释了平行取向和垂直取向边界区域的液晶取向状态。通过使用经退火处理的基板来制造具有几种尺寸的取向区域的LC单元，并且测量和评估LC透镜特性。研究了液晶层厚度与图案化面积比的关系，分析了有效光学延迟量，得到了定量结果.用有限差分法模拟了液晶指向矢的分布，并估计了液晶指向矢在界面处的取向。建立了获得良好折射率分布的光学器件设计准则.采用具有许多小直径（≤ 1 μm）微图案区域的玻璃基片制备液晶盒，通过改变微图案密度的有效面积比可以控制液晶盒的光学相位.根据这些结果，我们制作了折射率分布呈阶梯状或梯度状变化的液晶盒。然后，我们展示了新的液晶光学器件的偏转特性，并分析了它们的光学特性。这些设备的属性也可以通过向LC单元施加交流电压来改变。这些结果进行了检查和总结的研究工作。

1. We fabricate the liquid crystal (LC) cells by using a nematic LC and the substrates on which photo-lithographically partly patterned parallel alignment layers on the polyimide (PI) perpendicular alignment layer, where LC molecules are partly aligned parallel and perpendicular to the substrate, respectively.2. The optical retardation properties at the boundary region of parallel and perpendicular alignment layers are measured, and the liquid crystal orientation states at the boundary region of parallel and perpendicular orientations can be explained. The LC cells with several sized alignment regions are fabricated by using the alignment-treated substrates, and LC lens properties are measured and evaluated. The relations between the thickness of LC layers and the ratio of the patterned area are studied and effective optical retardations are analyzed, and then the quantitative results are obtained.3. The LC director distribution is simulated by the finite different method and the configurations of the LC director orientations at the boundaries are estimated. Then the design rules to attain the favorable refractive index distribution for optical devices are established.4. The LC cells are prepared using the glass substrates with many micro-patterned areas of small diameter (〜1 μm), and their optical phase can be controlled by changing the effective area ratio of micro-pattern density.5. According to these results, we fabricate the LC cells where the distributions of the refractive indices change stepwise or graded. Then, we demonstrate new LC optical devices with deflection properties, and analyze their optical properties. The properties of these devices can also be varied by applying an ac voltage to the LC cell.6. These results are examined and the research work is summarized.