溶液折射率及色散系数与浓度关系的椭偏测量研究  

Research of the relations between solutions refractive index and dispersion coefficient and concentration with ellipsometry measurement

作　　者：彭振阳[1] 吕斌[1] 顾晓敏[2] 鄢波[1] Peng Zhenyang Lv Bin Gu Xiaomin Yan Bo(College of Science,Zhejiang University of Technology, Hangzhou,310023 ,China School of Physics, Nanjing University, Nanjing, 210093, China)

机构地区：[1]浙江工业大学理学院,杭州310023 [2]南京大学物理学院,南京210093

出　　处：《南京大学学报（自然科学版）》2017年第1期151-158,共8页Journal of Nanjing University（Natural Science）

基　　金：浙江省新苗人才计划(2015R403024);浙江省环保厅科技计划(20120704002)

摘　　要：研究利用椭圆偏振法快速准确测量葡萄糖溶液浓度.首先基于椭偏测量的原理和液体宏观尺寸厚的特点,建立了溶液的单界面反射分析模型,针对该模型设计了由椭偏参量求解溶液折射率的算法.为了快速检测,该算法合理地忽略了葡萄糖溶液在短波段的消光系数并仍能够准确地测量出折射率.接着,利用该模型,对不同浓度的葡萄糖溶液的椭偏参数进行了测量.从椭偏参数拟合出了葡萄糖溶液的折射率,根据柯西公式,利用最小二乘法得到了折射率与柯西色散参数、溶液浓度之间的函数关系.然后用模型分析了葡萄糖溶液的光吸收对本测量方法的影响,进一步说明了模型的可靠性.最后,将实验拟合结果与参考文献值比较,发现此方案和棱镜全反射法和激光干涉法测量得到的折射率吻合得相当好,说明椭偏测量法具有较高准确度.A rapid and accurate method of measuring refractive index of glucose solution using ellipsometry was reported.Firstly,a single-interface reflecting analytic model was established based on the theory of elliptic measurement.Since aqueous solution always has large volume comparing with thin solid film,the reflection from the back surface of solution at the bottom of vessel can be ignored.In this method,the refractive index of solution can be obtained by the arithmetic designed with this model.In order to calculate the refractive index rapidly,the arithmetic ignored the extinction coefficient of the glucose solution in short wavelength region appropriately,by which the refractive index can be still achieved accurately.The influence of extinction coefficient on the calculation of refractive index was discussed.Then the elliptic parameters of glucose solution with different concentration were measured.According to the Cauchy formula,the refractive index of glucose solution was fitted using the elliptic parameters by the least square method as well as the relations among the refractive index,Cauchy dispersion factor and the concentration of glucosesolution.The deviation of measured elliptic parameters from the fitting one in short wavelength region was illustrated combing with the absorption spectrum and the effect of light absorption of glucose solution on the measurement was analyzed with the model,which manifests the reliability of our model further.Finally,comparing our results with the other literature values which were obtained by prism total reflection method and the laser interference method,the refractive index of glucose solution were similar among the values achieved by these different characterization technology.The variation tendency of the refractive index with the concentration of glucose solution was also examined by which the accuracy and practicality of our method were confirmed.

关 键 词：反射椭偏 葡萄糖溶液 折射率 色散 最小二乘法 

分 类 号：O436.3[机械工程—光学工程]