Light scattering from optical fibers with arbitrary refractive-index distributions

Abstract

A scattering theory is presented, which is capable of predicting the light-distribution pattern that arises when a clad optical fiber of arbitrary core refractive-index distribution is illuminated by a laser beam perpendicular to its axis. Theoretical predictions are compared to experimental results in the backscattering direction, with excellent agreement for fibers of practical interest having core and cladding diameters on the order to 50 and 150 µm, respectively. Considerable sensitivity to parameter variations has been observed and implications for diameter and refractive-index distribution determinations are discussed.