Formulas for calculating the refractive index profile of optical fibers from their transverse interference patterns

Abstract

A set of successive approximation formulas for calculating the refractive index profile of optical fibers from their transverse interference patterns has been derived. The probing ray refraction due to the index gradient in the core is corrected for by these formulas, and the accuracy of index determination is improved. The error is confirmed to be less than 3 x 10(-3)% of the index difference by means of computer simulations. The index profiles of some optical fibers are practically determined with the help of these formulas.