基于M-Z光纤干涉仪测量极化聚合物的电光系数

Measurement of Linear Electro-optic Coefficients of Poled Polymers by anOptical Fiber M-Z Interferometer

提出了采用Mach Zehnder(M Z)光纤干涉仪的电光聚合物电光系数测量方法,对其测量原理进行了分析,研究了光纤干涉仪的臂长差、样品的插入损耗对系统可见度的影响,讨论了通过合理设置耦合器的耦合系数提高系统测量性能的方法。系统具有较好的稳定性和较高的灵敏度,既适合于聚合物薄膜也适合于聚合物波导的测量,系统干涉可见度为0.86,可分辨的最小相位变化约为6×10-6 rad。该系统可以同时测量2个独立的电光系数γ13和γ33,使用该系统测得一种有机/无机杂化材料ASD/SiO2 TiO2 极化后的电光系数为γ13=0.72±0.01 pm/V和γ33=2.8±0.01 pm/V。

A method to determine the electro-optic coefficients of poled polymer films by using an optical fiber Mach-Zehnder (M-Z) interferometer was presented. Theoretical analysis on the measurement principle was given. The factors limiting the visibility of the system, such as the interference beam length difference and the sample insertion loss, were analyzed in detail. The system performance has been improved by careful choice of the coupling ratios of the couplers building up the interferometer. The system has good stability and high sensitivity. It's suitable for both polymer films and polymer waveguide. The measured visibility of the system is 0.86. A minimum phase of 6 × 10-6 rad can be detected. Two independent electro-optic coefficients components, γ13 and γ33, can be determined by the system. The coefficients of a poled organic/inorganic hybrid material, ASD/SiO2-TiO2, measured by this system are γ13 = 0.72 ± 0.01 pm/V, γ33 = 2.8 ± 0.01 pm/V.