A modified Poincare sphere technique for the determination of polarization-mode dispersion in the presence of differential gain/loss

Summary form only given. A simple and robust technique for the measurement of the principal states of polarization (PSP) and their differential group delay (DGD) is important for the characterization of polarization dispersion in optical communication links. One common technique for this kind of measurement is known as the Poincare sphere method. By fitting concentric circles to the trajectories traversed on the Poincare sphere by the output polarization state when the frequency is changed, both the PSPs and the DGD can be identified. While it is a simple technique, it has one major drawback: it is not suitable for optical systems that have polarization-dependent loss or gain. In this paper we propose a modified Poincare sphere method that is valid in the most general case.