第18卷第6期 2010年6月
文章编号
1004-924X(2010)06-1264-07
光学精密工程
Optics and Precision Engineering
透明毛细管管壁折射率的无损测量
李强，苏光辉，张瑞凯，孙丽存，普小云
（云南大学物理科学技术学院物理系，云南昆明650091）
Vol.18No. 6
Jun.2010
摘要：介绍了一种无损测量透明毛细管管壁折射率的方法。该方法利用平行光经过装有不同已知折射率标准液体的毛细管后会聚焦点位置不同的原理，通过CCD对会案焦点位置成像后的图像进行判断，计算出毛细管外轮廊位置和焦距，进而计算出毛细管管壁的折射率，其测量精度可达0.005，分析了毛细管内外径对管壁折射率测量的影响，结果表明，管壁越厚，测量精度越高；同时对毛细管管壁折射率灵敏度和成像系统的景深值进行了计算和比较，结果显示，标准液体折射率越低，标定精度越高。
该方法使用设备简单，操作方便，便于对图像观察和识别，实现了对毛细管管壁折射率的无损精确测量。关键调：折射率测量；无模测量；毛细管；焦距；测量精度
中图分类号：TB96：TH741.4
文献标识码：A
doi;10.3788/OPE,20101806.1264
Nondestructivemeasurement of refractive index of transparency capillary
LI Qiang,SU Guang-hui,ZHANGRui-kai,SUN Li-cun,PU Xiao-yun(Departmentof Physics,School of Physical Science and Technology,
YunnanUniversity，Kunming650091,China)
Abstract: A novel nondestructive measuring method for the refractive index of a transparency capillary is introduced in this paper. When a collimated light passes through a capillary filled in a standard liq uid with known refractive index, the focal position is dependent mainly on the wall-material of the capillary. On the basis of the above, the position and focal length of a capillary are imaged by a lens onto a CCD chip accurately, when the capillary is filled in two different liquids with known refractive indexes, respectively. Then, the refractive index of the wall- material is obtained by measuring and calculating two positions and focal lengths separately.The measurement accuracy of refractive index is better than 0. o05.The effects of measuring parameters, including inner and outer diameters of the capillary, the refractive index of satandard liquid, as well as the image depth and sensitivity of refrac-tive index on the measuring precision are analyzed. It is shown that the thicker capillary wall is,the higher the measuring precision is, and the lower the refractive index of standand liquid is,the higher the calibrating accuracy is, The introduced method is characterized by simple equipment, easy to oper ation, convenient to observe and its measurement precision of refractive index can meet the require-ments of general scientific research and experiments,
Key words: refractive index measurement; nondestructive measurement; capillary; focal length;
measurement accuracy
收精日期：2009-07-15；修订日期：2009-10-14.
基金项目：国家自然科学基金资助项目（No.60877037)；国家和云南省大学生创新基金资助项目