为了研究胆甾相平面态液晶(Cholesteric liquid crystal with planar texture, CLCPT)层在上下表面取向平行(Parallel anchoring, PA)和上下表面取向垂直(Orthogonal anchoring, OA)两种液晶盒中指向矢排布随温度变化的特征, 分别制备了PA和OA两种CLCPT液晶盒样品。构建了由梯形低折射率棱镜、匹配液、CLCPT液晶盒组成的全漏导模结构, 采用全漏光学导波(Fully leaky optical guided wave, FLOGW)方法获得了在不同温度下反射率随内角(测试光线入射到CLCPT层上的入射角)变化的导波实验曲线Rss, 将其与基于液晶弹性理论和多层光学理论模拟出的同一温度下的理论导波曲线Rss进行拟合, 精准分析出在PA和OA盒内, CLCPT指向矢排布随温度变化的特征。此外, 应用控制变量法测量出不同温度下胆甾相液晶(Cholesteric liquid crystal, CLC)双折射率实际参数值。

In order to study director arrangement of the cholesteric liquid crystals layer with planar texture (CLCPT) in parallel anchored (PA) and orthogonal anchored (OA) cells with temperature changes, two samples of CLCPT in PA and OA cells were prepared respectively. A fully leaky guide mode structure consisting of two trapezoidal low refractive index prisms, the refractive index matching liquids and one CLCPT cell was constructed. The method of fully leaky optical guided wave (FLOGW) was introduced to measure the experimental curve of reflectivity Rss with inner angle (the incident angles of the test light incident on the CLCPT layer) at different temperatures. The temperature dependence of the theoretical curves revealed by simulations based on elastic theory of liquid crystal and multi-layer theory was in agreement with the experiment result, and the characteristics of CLCPT director arrangement with temperature changes in PA and OA cells were accurately analyzed. In addition, the actual birefractive index values of cholesteric liquid crystal (CLC) at different temperatures were measured by the control variable method.