研究二阶偏振模色散(PMD)对高斯光脉冲在单模光纤中传输产生的影响,给出输出光脉冲的时域表达式.分析表明,输出光脉冲在每个基本偏振态上仍保持高斯形状,但其频率啁啾及脉宽等特性都已改变,文中对这些变化与二阶偏振模色散之间的关系进行了讨论.通过比较10 Gb/s和40 Gb/s的光传输系统中二阶偏振模色散的影响,可以发现,若规定脉冲展宽不能超过脉宽的十分之一,40 Gb/s系统所能容忍的二阶偏振模色散极限值比10 Gb/s系统小一个数量级.

The second order PMD effect on Gaussian pulse propagation in single mode optical fiber is studied. The explicit expression of second order PMD induced pulse distortions is given in the time domain. It is found that the output pulse in each basic state of polarization retains Gaussian shape but some characters such as the frequency chirp and the pulse width have changed. The relationship between these changes and second order PMD is analyzed. The second order PMD influences in 10 Gbit/s and 40 Gbit/s systems are compared. It is found that the tolerable value of second order PMD in 40 Gbit/s systems is one order of magnitude lower than in 10 Gbit/s systems if the pulse broadening must not exceed one tenth of the pulsewidth.