Demonstration of an optimal polarization scrambler for long-haul optical amplifier systems

Polarization scrambling of the input signal in a long-haul erbium-doped fiber amplifier (EDFA) system is studied both experimentally and theoretically. Demonstration of an optimal polarization scrambler is achieved ensuring complete suppression of the signal decay caused by polarization dependent gain (PDG) in EDFAs. Best performance of the system is attained without imposing severe requirements on the polarization scrambler in terms of residual degree of polarization. Close agreement between measurements and calculations provides a valuable validation of the assumed linear dependency of the PDG differential gain with the degree of polarization of the light.<>