Automatic maximum-minimum search method for accurate PDL and DOP characterization

A fully automatic deterministic maximum-minimum search method for fast accurate polarization-dependent loss (PDL) and degree of polarization (DOP) characterization is described. It is shown theoretically, based on a three-dimensional (3-D) surface model, that the method can unambiguously determine PDL and DOP values. Because it measures PDL and DOP values according to their, definitions and without the need for scanning over a large number of polarization states or engaging in extensive intermediate calculations, this method provides the attractive features of high speed, wide measurement range, wavelength insensitivity, and calibration-free operation. The new PDL/DOP characterization method was experimentally demonstrated in a prototype instrument using an in-line polarization controller with ultralow activation loss and PDL.