Optical fiber refractive index profile synthesis from near field

Abstract – A new and accurate refractive index profile synthesis method for optical waveguides is demonstrated using the transmitted near electric field data. This method is based on an inverse transmission line technique. From Maxwell’s equations, we derive a transmission line equivalent circuit for the refractive index profile of a cylindrical dielectric waveguide. We demonstrate how to use this model and carry out the inverse problem and synthesize the exact refractive index profile numerically from near field data. Based on knowledge of the electric field, we demonstrate results of numerical reconstruction of step index, parabolic, and segmented optical fibre refractive index profiles. The accuracy of the reconstructed waveguides is examined numerically.