Dynamic PMD compensation in 4 x 10 Gb/s optical time-division multiplexed transmission system

Using the degree of polarization as feedback signal to detect the polarization mode dispersion (PMD) variation in the fiber links, an experiment of dynamic adaptive PMD compensation in 4 x 10 Gb/s optical time-division multiplexed (OTDM) transmission system is reported. The PMD compensator consists of a polarization controller and a variable delay line with four degrees of freedom. Based on the variable step-size peek search algorithm, the performance of the PMD compensator is assessed in the eye pattern of a received signal. It is shown that the maximum compensated differential group delay is 25 ps, i.e. one bit period, and the compensation time can be less than 50 ms.