Dispersion-shifted fiber polarization scrambler based on Faraday effect

Demonstration of an all-fiber polarization scrambler based on the Faraday effect is carried out. The device has been constructed using dispersion-shifted fiber that has a major tolerance to bends than standard single-mode fiber. Results about the fiber Verdet constant when 1550-nm light is launched are presented. The performance of the constructed device is also shown. Main features are insertion losses as low as 0.4 dB and scrambling frequency up to 20 kHz. Although here we emphasize its application to low-frequency heterodyne detection, the scrambler is applicable to other systems that are polarization dependent. In particular, it would be useful to overcome problems originated by polarization dependent gain in erbium-doped fiber amplified systems.