中文摘要：

利用偏光干涉理论，通过对BL-009型向列相液晶透射比的测试，分析了液晶透射比随磁场的变化情况，并对液晶的磁控双折射效应进行了研究．实验在室温20℃下用JG-3型连续可调磁场仪对液晶盒施加垂直于其表面的磁场，用CT5A型特斯拉计准确读出磁场强度数值，使液晶盒光轴方向与起偏镜和检偏镜偏振方向成45°，分别测出了起偏镜和检偏镜偏振方向平行和垂直时的透射光强度．通过数学函数拟合，得出了液晶的双折射率随磁场的变化规律，即：当磁场强度大干液晶的闳值磁场时．拟会函数能很好地描述液晶磁控双折射率的变化规律．

英文摘要：

The polarized light interference method is employed to measure the birefringence of liquid crystal. The transmission of nematic liquid crystal magnetism-dependent are tested by using JG-3 type continuous tunable magnetism device in room temperature 20℃. When the angle among liquid crystal cell optical axis and polarizer and polarization analyzer is 45°, the transmission light intensity is respectively tested under parallel and uprightness of polarizer and polarization analyzer. The method of mathematic function fitting is employed to obtain the rule of liquid crystal birefringence magnetism-dependent, the theory very agree with practice. After analyzing the experimental result, Magnetism Controlled birefringence of liquid crystal is obtained. The obtained result is useful for the design and manufacturing, application of liquid crystal device.