Research on simultaneous measurement of the phase and group indices and the thickness of transparent plates and the scattering medium by the low coherence interferometry

低相干干涉法同时测量透明板和散射介质的相位指数、群指数和厚度的研究

基本信息

批准号：
09555009
负责人：
HARUNA Masamitsu
金额：
$ 5.7万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

The research has been made to demonstrated the practical low coherence interferometer system which can provide simultaneous measurement of the phase and group indices and the thickness of transparent plates and the scattering medium such as biological tissues. Major research results are described in the following.1. We proposed and demonstrated a novel technique for simultaneous 'measurement of the phase and group indices and the thickness of a measured object. The technique is based on the low coherence interferometry combined with precise translation stages. In the experiment using the object scanning method, the measurement accuracy of 0.2% or less was attained for nearly 1-mm thick transparent plates. To realize a stable and compact measurement system, the low coherence interferometer consisted of micro-optic components on a optical bench of 50 x 60cm^2.2. On the basis of our proposed method, the automatic measurement of n_p and t taking the chromatic dispersion of the sample into account and the measurement n_p, n_g and t using the specific sample holder were successfully achieved within three minutes.3. The measurement accuracy of <1% was achieved even when the sample is as thin as 20mum, because of compensation for the unbalance of the chromatic dispersion between the sample and reference arms in the interferometer and using the alternative scanning method.4. Moreover, our measurement system is applicable for accurate measurement of refractive index of the scattering medium such as biological tissues. When the stage resolution is 1mum, the measurement accuracy of 1% or less is guaranteed for the sample thickness t more than 100mum. Simultaneous measurement of n and t were successfully achieved for a human nail, tooth, chicken tissue and a crustacean which has multiple layers.

研究展示了实用的低相干干涉仪系统，该系统可以同时测量透明板和生物组织等散射介质的相位指数、群指数以及厚度。主要研究成果如下： 1．我们提出并演示了一种同时“测量相位和群指数以及被测物体厚度的新技术”。该技术基于低相干干涉测量与精确平移台相结合。在使用物体扫描法的实验中，对于近1毫米厚的透明板，测量精度达到了0.2%以下。为了实现稳定、紧凑的测量系统，低相干干涉仪由安装在50 x 60cm^2.2光具座上的微光学元件组成。基于我们提出的方法，在三分钟内成功实现了考虑样品色散的n_p和t的自动测量以及使用特定样品支架的n_p、n_g和t的测量。 3．由于干涉仪中补偿了样品和参考臂之间的色散不平衡，并采用了交替扫描方法，即使样品薄至20μm，测量精度也能达到<1%。 4．此外，我们的测量系统适用于精确测量生物组织等散射介质的折射率。当载物台分辨率为1μm时，对于样品厚度t大于100μm的样品，可保证1%以下的测量精度。成功实现了对人类指甲、牙齿、鸡组织和多层甲壳动物的 n 和 t 的同时测量。