Reflectometric measurements of polarization properties in optical-fiber links

Polarization sensitive reflectometric measurements are effective tools for the characterization of polarization properties of optical-fiber links. These techniques show two advantages compared with the standard ones: they can perform measurements using only one fiber end (both for transmission and for reception of the probe signal) and, most important, they can characterize the local evolution of the polarization properties of the fiber link. Reflectometric measurements of differential group delay and fiber birefringence have been already successfully performed. More recently, the possibility of measuring also polarization dependent loss has been theoretically explored. In this paper the theory and main applications of polarization sensitive reflectometric techniques are reviewed.