Digital PDL Compensation in 3D Stokes Space

A Stokes space based technique for digital polarization-dependent losses (PDL) monitoring and compensation is proposed. The channel PDL monitoring is carried out with a resolution of 0.15 dB by computing the mean point of the signal samples represented in the three-dimensional Stokes space. The presented compensation technique is based on rotations and translations of the signal samples in the Stokes space, and provides a PDL compensation up to 2.5 dB. Error vector magnitude results show a gain of about 3 dB (assuming a PDL value equal to 1.5 dB) to a Stokes space based polarization demultiplexing technique without PDL compensation.