全漏光导波技术确定液晶材料的挠曲电系数  

Determination of the Flexoelectric Coefficient in Liquid Crystal Using Fully-leaky Optical Guided Wave Technique

作　　者：郑桂丽[1,2,3] 张辉[3] 叶文江[3] 张志东[3] 宋宏伟[4] 宣丽[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室,长春130033 [2]中国科学院大学,北京100049 [3]河北工业大学理学院,天津300401 [4]吉林大学电子科学与工程学院,长春130021

出　　处：《光子学报》2014年第12期51-55,共5页Acta Photonica Sinica

基　　金：国家自然科学基金(Nos.11374087;11274088;11304074);河北省自然科学基金(No.A2014202123);河北省教育厅项目(Nos.Z2012061;Z2012067;QN2014130);河北省高校重点学科资助

摘　　要：利用全漏光导波技术,测量负性向列相液晶材料MS-N01300-000的展曲和弯曲挠曲电系数之和.根据液晶弹性和多层光学理论得到同一电压下不同挠曲电系数的反射率随内角(入射到液晶层角度)的理论变化曲线.实验中,将液晶材料灌注到混合排列向列相液晶盒中,在液晶盒上分别加交流电和直流电,采用全漏光导波技术得到反映液晶指向矢分布的液晶波导反射率随内角变化曲线.实验发现,由于液晶挠曲电作用,同一电压值下反射率随内角变化曲线发生微小移动.对比理论与实验曲线,由曲线移动距离得到MS-N01300-000液晶材料展曲和弯曲挠曲电系数之和为2.5×10-11 C/m.The fully-leaky optical guided wave technique was employed to measure the sum of splay and bend of flexoelectric coefficients in the negative nematic liquid crystal MS-N01300-000. The curves of reflectivity versus the internal angle （the angle of incident light to liquid crystal） with different flexoelectric coefficients under the same value of voltage can be calculated by the elastic theory of liquid crystal and the multi-layer optical theory. The director profile of the mentioned liquid crystal parameter filled in hybrid aligned nematic liquid crystal cell for different external applied voltages can be reflected by the curves of reflectivity versus the internal angle using the fully-leaky optical guided wave technique experimentally. There is a small move for the curves of reflectivity versus internal angle when alternating current voltage or direct current voltage with the same value is applied to the hybrid aligned nematic liquid crystal cell,which is induced by the flexoelectrieity of liquid crystal. The approximate value of the sum of splay and bend of flexoelectric coefficient of MS-N01300-000 is 2.5 × 10^-11C/m by comparing theoretical results with experimental data.

关 键 词：光导波技术 负性向列相液晶 挠曲电系数 混合排列向列相 弹性理论 多层光学理论 

分 类 号：O753.2[理学—晶体学]