Distributed Characterization of Few-Mode Fibers Based on Optical Frequency Domain Reflectometry

A novel technique to measure differential group delay and modal birefringence along few mode fibers is presented. The method relies on the analysis of the spectral correlation between two properly-selected sections of the fiber's Rayleigh-backscattered trace, acquired with an optical frequency domain reflectometer. Experiments performed on a two-mode-group fiber confirm the viability of the method.