Sokkar T Z
Appl Opt. 1992 Mar 20;31(9):1229-33. doi: 10.1364/AO.31.001229.
A mathematical formula is derived from the multiple-beam Fizeau fringers crossing an elliptical multilayer fiber. A formula for the two-beam interference fringes crossing this fiber is also given. A model that divides the elliptical fiber cross-section into elliptical zones of constant refractive index is assumed. The index profile of the poly(aryl-ether-ether-ketone) fiber is calculated by using the mathematical formulas. Microinterferograms of both the multiple-beam Fizeau fringes and the totally duplicated image of the fiber from a two-beam intereference microscope are used for the determination of the refractiveindex profile of the fiber. The cross-sectional shape is determined from the diffraction pattern of a He-Ne laser beam. Microinterferograms are given for illustration.
推导了穿过椭圆形多层光纤的多光束斐索条纹的数学公式。还给出了穿过该光纤的双光束干涉条纹的公式。假定了一个将椭圆形光纤横截面划分为具有恒定折射率的椭圆形区域的模型。通过使用这些数学公式计算聚（芳基 - 醚 - 醚 - 酮）光纤的折射率分布。多光束斐索条纹的微干涉图以及来自双光束干涉显微镜的光纤完全重复图像用于确定光纤的折射率分布。横截面形状由氦氖激光束的衍射图案确定。给出微干涉图以作说明。
