An improved method for the distributed measurement of the chromatic dispersion of an optical fiber using a wavelength tunable OTDR

In this paper, we present an improved distributed measurement of the chromatic dispersion of an optical fiber, which is based on the analysis of a set of bidirectional optical time domain reflectometer (OTDR) traces collected over the wavelength range of interest. The method uses the known mode field diameter and chromatic dispersion of a reference fiber to reduce the significance of the approximations made in the technique and hence improve upon previous methods. The validity of the approximations is verified via a numerical simulation and experimental measured results are given for both step-index and dispersion shifted fibers. Our results show that this technique is well adapted to the distributed chromatic dispersion measurement requirements of an optical fiber factory.