Theory of polarization shift keying modulation

A rigorous analysis of digital coherent optical modulation schemes using the state of polarization as the modulating parameter is presented, which permits to obtain the exact performance of all the polarization-based modulation schemes proposed in the literature so far, including a differential demodulation scheme, named DPOLSK, which does not require either electrooptic or electronic polarization tracking. Preliminary results involving multilevel transmission schemes based on the state of polarization are introduced. A spectral analysis of POLSK signals is also proposed.