Presby H M, Astle H W
Bell Laboratories, Crawford Hill Laboratory, Holmdel, NJ 07733, USA.
Rev Sci Instrum. 1978 Mar;49(3):339. doi: 10.1063/1.1135403.
An electronic technique to make fringe displacement measurements on the output field of an interference microscope to 1/1000 of a fringe, not including systematic errors, is described. The method, based upon line-selected video signal analysis, is applied to the evaluation of the refractive index profile of a graded index optical fiber. The index difference at a given point between the core and cladding is determined to better than 1 part in 10(5), implying a precision in the profile parameter alpha of +/-0.005, an order of magnitude better than existing techniques.
描述了一种电子技术，该技术用于在干涉显微镜的输出场中进行条纹位移测量，测量精度可达条纹的1/1000，不包括系统误差。该方法基于所选行的视频信号分析，应用于渐变折射率光纤折射率分布的评估。确定纤芯和包层在给定点的折射率差优于10^5分之一，这意味着分布参数α的精度为±0.005，比现有技术高一个数量级。
