| Abstract: | In this article the Fourier transform method is applied to analyze multiple‐beam interference Fizeau fringes. The real part of the inverse Fourier transform is used to estimate a theoretical pattern. This pattern coincides with the experimental one. A derivative‐sign binary image of the interference pattern is also used in automated determination of the contour line of the fringe pattern, regardless of the quality of this pattern. A correlation between the pixel size and the accuracy of the measured fiber refractive index is presented. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 475–484, 2002 |
