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

1. 我们使用向列LC和衬底来制造液晶（LC）电池，衬底上的聚酰亚胺（PI）垂直排列层上的光刻部分图案平行排列层，其中LC分子分别部分平行和垂直于衬底。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，并解释了平行取向层和垂直取向层边界区域的液晶取向状态。利用经过对准处理的衬底制备了具有不同尺寸对准区的LC细胞，并对LC透镜的性能进行了测量和评价。研究了LC层厚度与图像化面积比的关系，分析了有效光学延迟，得到了定量结果。用有限差分法模拟了导波器的分布，估计了导波器在边界处的取向构型。在此基础上，建立了实现光学器件良好折射率分布的设计原则。4 .利用具有许多直径小（~ 1 μm）的微图案区域的玻璃基板制备LC电池，通过改变微图案密度的有效面积比可以控制其光学相位。根据这些结果，我们制作了折射率分布呈阶梯或梯度变化的LC电池。然后，我们展示了具有偏转特性的新型LC光学器件，并对其光学特性进行了分析。这些器件的特性也可以通过对LC单元施加交流电压来改变。对这些结果进行了检验，并对研究工作进行了总结。

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.