Enhanced PMD monitoring with frequency-resolved SOP rotation by self-phase modulation

A self-phase modulation (SPM)-assisted polarization-mode-dispersion (PMD) monitoring scheme based on frequency-resolved state-of-polarization rotation is proposed. The use of broadened signal spectrum induced by SPM not only relaxes the filter requirement and reduces the computational complexity, but also improves the estimation accuracy, and extends the monitoring range of the pulsewidth. In this letter, PMD monitoring using this enhanced scheme was studied and experimentally demonstrated with much reduced estimation error, to around 2%, for a 10-Gb/s optical system with 28-ps full-width at half-maximum pulsewidth. In addition, the operation range for the proposed scheme was characterized.