A novel adaptive PMD compensation system based on PSO algorithm

An adaptive PMD compensation system used in WDM telecommunication network has been proposed, in which a polarization scrambler was combined with orthogonal polarization splitting detection to achieve multi-channel degree of polarization (DOP) detection. Optical signal-to-noise ratio (OSNR) is obtained from the measurement of P-s and P-N, then the monitoring of DOP can be implemented according the relationship of OSNR and DOP. The searching and tracking of DOP is achieved by PSO algorithm. After the D/A conversion, the voltages ranging from 0 to 10 V are performed on the polarization controller to adjust the principle polarization state of signal. Thus, a close-loop feedback control module can be built up, and after several iterations, the optimum of DOP is obtained and the adaptive PMD compensation is achieved. After compensation, the eye opening is improved obviously, which demonstrates the feasibility and effectiveness of the compensation method.