Abstract:

A numerical model is founded to analyze the performance of two sampling modes for polarization degree as controlling signal with various polarization mode dispersion compensators in 40?Gbit/s optical fiber communication. numerical simulation results including the compensated bit error rate(BER)and polarization degree of 1000 sampling points show that when single state of polarization sampling mode is used in two stages and three stages polarization mode dispersion (PMD) compensator with more than four degrees of freedom, the numbers of degree of freedom for the compensators should not be more than four, otherwise, the compensation algorithm will be plunged in local maximum to cause severe PMD that increase bit error. So, another sampling method is proposed to be suit for three section PMD compensator, in which shortest axis lengths of degree of polarization (DOP)ellipsoid is used as the feedback signals. The performance of DOP ellipsoid is evaluated by means of numerical simulations with threesection compensator, which is better than that of single state of polarization sampling mode.

Key words: optical communication, polarization mode dispersion compensation, degree of polarization