A fully polarimetric optical time-domain reflectometer

We report the implementation of the first fully polarization sensitive optical time domain reflectometer (POTDR). This nondestructive measurement technique, requiring access to one fiber end only, enables the determination of both the linear and twist induced circular birefringence distribution along the fiber. This information, combined with a knowledge of the mode coupling length, enables the evaluation of the polarization mode dispersion (PMD) properties of fibers and optical cables exhibiting both types of birefringence, as well as identifying fiber sections with and without twist. The POTDR, which has a spatial resolution of 0.3 m, could also be used for monitoring the birefringence properties of fibers at the manufacturing stage, leading to optimization of fabrication techniques to minimize PMD.