不同调制码型的偏振模色散补偿研究

在40Gb/s的光纤通信系统中,用三段模拟器模拟光纤传输中的一阶与二阶偏振模色散(PMD),采用单偏振态的偏振度(DOP)作为多级PMD补偿器的反馈信号,对归零(RZ)码、非归零(NRZ)码、载波抑制归零(CSRZ)码和啁啾归零(CRZ)码分别进行四个自由度的一级、六个自由度的二级和十个自由度的三级PMD补偿器的补偿.仿真得到了四种码型的DOP与误码率(BER)的关系,同时补偿后的BER、DOP和PMD的变化关系表明,对RZ和NRZ码采用二级补偿器的效果比一级和三级补偿器要好得多,对CSRZ码和CRZ码采用单偏振态的DOP作为反馈信号进行PMD补偿的效果并不理想.

Comparison of different modulation formats for polarization mode dispersion compensation

The effect of different modulation formats for multi-stage polarization mode dispersion (PMD) compensators with degree of polarization (DOP) of single state of polarization as feedback signal was studied and compared by numerical simulation in 40Gb/s optical fiber communication. The PMD was proposed to be produced by three sections PMD emulator including first and second PMD. The correlation between DOP and bit error rate (BER) for return-to-zero (RZ),non-return-to-zero (NRZ),carrier suppressed return-to-zero (CSRZ) and chirp return-to-zero (CRZ) format was obtained. We show that the efficiency of two-stage PMD compensators is best for RZ and NRZ format with DOP of single SOP as feedback signal according to the relationship of the compensated DOP,DGD and BER. And the effect of compensation is not ideal for CSRZ and CRZ format all the time.