对40 Gb/s光纤通信中归零码和非归零码光脉冲的偏振度随二阶偏振模色散的变化规律进行了数值模拟,结果表明由于二阶偏振模色散的影响,偏振度的变化趋势呈现出震荡性,二阶偏振模色散对归零码的偏振度要比非归零码的偏振度影响明显;同时搭建了偏振模色散补偿系统,对系统进行数值模拟和实验所得到的结果都表明,以偏振度作为反馈信号,采用粒子群优化算法作搜索算法能够有效地对归零码和非归零码系统的一阶及高阶偏振模色散进行自适应补偿。

The degradation of signal degree of polarization with second order polarization mode dispersion in 40 Gb/s RZ and NRZ optical communication is analyzed by numerical simulation. The results show that the degradation of signal degree of polarization is vibrated by second order polarization mode dispersion. The effect of higher-order polarization mode dispersion on degree of polarization of NRZ and RZ code are also numerically analyzed, the results show that the effect of second polarization mode dispersion on degree of polarization of RZ code are more evident than that on NRZ code. A experiment system is set up to compensate the first and high order polarization mode dispersion effectively by degree of polarization as feedback signal and PSO as compensation arithmetic for RZ and NRZ code system.