Refractive and dispersive measurements of polymer optical fibers and fiber preforms

We present another method for determining the refractive index profile of polymer optical Aber preforms using reflection of a laser beam undergoing harmonic displacements. The index profile is obtained by an iterative procedure based on a series expansion of the Fresnel reflection coefficient. Profile results show agreement with the Direct Deflection Method. In addition, the refracted near field technique is applied to a polymer optical fiber to measure its refractive index profile, A bandwidth measurement of a graded-index fiber is also presented.