Reflectometric measurements of PMD properties in long single-mode fibers

Polarization sensitive reflectometric measurements are effective tools for the characterization of polarization properties of optical-fiber link. The field of application of these techniques depends on whether they use a continuous wave source or a pulsed source to generate the probe signal. In the first case, reflectometric techniques may be successfully applied to perform single-end measurement of differential group delay and polarization dependent loss. In the second case - that is the case of polarization sensitive optical time domain reflectometry - the local birefringence of a single mode fiber can be measured and characterized. In this paper the theory and the applications of polarization sensitive reflectometric techniques are reviewed.