马赫-曾德尔干涉法测量液体折射率的改进

Development of measurement for refractive index of liquid by Mach-Zehnder interferometer

中文关键词: 测量,折射率,干涉,图像处理

英文关键词: measurement, refractive index, interference, image processing

中文摘要:

      液体折射率是物理、化学、生物等学科的重要基础数据。干涉法是测量液体折射率的常用方法,利用实验本体的旋转角度和干涉条纹变化数量的函数关系来测量液体折射率。基于马赫-曾德尔干涉法,改进了实验原理,利用线性关系消除了实验本体产生的附加干涉条纹,建立了一种特殊的数据处理方法精确得到了θ=0°即激光垂直入射本体视窗的位置。使用蒸馏水对液槽厚度进行了校核,测量了T=20℃下乙醇、丙酮和环己烷的折射率验证了实验系统的可靠性。同时对实验系统的测量精度进行了分析,实验的测量不确定度为10_-4量级。

英文摘要:

      Refractive index of liquid is a important basic datum for physical, chemical, biological, and other disciplines. Interferometry is a useful method for measuring liquid refractive index, using the function between the interference fringe shifts and the rotation angle of the sample. We present a Mach-Zehnder interferometric system to measure liquid refractive index. A route to eliminate the effects of additional interference fringe shifts from liquid cell is presented and a specific data process to check the position of θ=0° is used, which greatly simplifies the process of measurement. We measured the refractive index of distilled water for revising the thickness of liquid sample, and refractive indices of ethanol, cyclohexane and acetone were measured at T=20oC to verify the system. Meanwhile, we analyzed the uncertainty of experiment system, which is in the order of 10_-4.