Determination of the refractive-index profile of light-focusing rods: Accuracy of a method using interphako interference microscopy

Yasuji Ohtsuka, Yasuhiro Koike

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Two analysis procedures to determine the refractive-index profile using Interphako interference microscopy are compared for accuracy: (I) expressing the. profile as a five-nomial equation (proposed previously by Ohtsuka and Shimizu); (II) considering ray bending due to the index gradient and using Abel inversion (proposed by ga et al.). Computer simulations indicate that the errors of both procedures are comparable except for index mismatching between the specimen periphery (np) and immersion oil (n2) where Analysis (I) is more accurate than Analysis (II). The partial splitting method is more practicable than total splitting for a rodlike specimen. In addition, the improved partial splitting procedure facilitates reduction of error. The index profiles of the two selected light-focusing plastic rods (LFR) were calculated with these two procedures in various conditions. The correlation between resulting profiles and measuring conditions agreed with the simulations. It is concluded that Analysis (I) is preferable to Analysis (II) when np ≠ n2 and that the improved partial splitting procedure is a practicable method for determining the index profile of a LFR.

Original languageEnglish
Pages (from-to)2866-2872
Number of pages7
JournalApplied Optics
Issue number16
Publication statusPublished - 1980 Aug 15


ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Engineering (miscellaneous)
  • Electrical and Electronic Engineering

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