基于激光回馈效应的液晶双折射特性测量  

Birefringence measurement of liquid crystals based on laser feedback effect

作　　者：李继扬[1,2] 谈宜东[1] 吴季 张书练[1] Li Jiyang Tan Yidong Wu Ji Zhang Shulian(State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China School of Instrumentation Science and Opto-electronics Engineering, Beihang University, Beijing 100191, China Castech Inc., Fuzhou 350003, China)

机构地区：[1]清华大学精密仪器系精密测试技术及仪器国家重点实验室,北京100084 [2]北京航空航天大学仪器科学与光电工程学院,北京100191 [3]福建福晶科技股份有限公司,福建福州350003

出　　处：《红外与激光工程》2017年第3期107-112,共6页Infrared and Laser Engineering

基　　金：国家自然科学基金(61475082)

摘　　要：准确的双折射特性测量对于液晶的实际应用具有重要意义。研究了液晶材料的工作原理,以激光回馈效应为基础,搭建了各向异性外腔回馈双折射测量系统,对不同驱动电压下液晶的双折射特性进行测量。测量结果表明,各向异性外腔回馈双折射测量系统测量精度在0.3°之内;通过施加0~24V交流电压,液晶材料双折射率在2.74×10^(-1)~2.39×10^(-3)范围内变化,对应各向异性呈现出460°~5°的大范围位相延迟值。电压范围在0.7~2V时,电压-双折射率关系表现出较好的线性度,通过线性拟合对该范围内电压-双折射率关系进行计算,其线性度优于95.5%。液晶材料可以提供稳定的位相延迟,同一电压值下的位相延迟短期重复性优于0.52°,长期重复性优于4.5°。The precise measurement of the birefringence in the liquid crystals has significant meaning for practical applications. The working principles of the liquid crystals were analyzed. The laser anisotropy external cavity feedback system was built based on the laser feedback effect. The anisotropy of the liquid crystals under different voltages was measured. The measurement results show that the accuracy of the laser anisotropy external cavity feedback system is within 0.3°; By imposing different voltage from 0 to 24 V, the birefringence changes from 2.74×10-1 to 2.39×10-3, corresponding to the large range phase retardation of 460° to 5°. With the voltage in the range of 0.7 V to 2 V, the relationship between the voltage and the birefringence is linear and its linearity is better than 95.5%. The liquid crystals can provide stable phase retardation, the short-term repeatability is better than 0.52° and the long-term repeatability is better than 4.5°.

关 键 词：液晶材料 双折射特性 位相延迟 激光回馈效应 各向异性外腔回馈 

分 类 号：TH741[机械工程—光学工程]