不同模式耦合下偏振模色散几率分布的研究

研究了偏振模色散的统计特性，在不同模式耦合条件下，应用蒙特-卡罗方法模拟偏振模色散矢量的几率分布，并对模拟结果进行了函数拟合。发现随着耦合次数增加差分群时延的几率分布从一个类似δ函数分布逐渐过渡到麦克斯韦分布；在一定的耦合下，几率分布可以呈现高斯分布。对偏振模矢量的两个方向余弦进行统计分析，发现随着耦合次数的增加，偏振模矢量两个方向余弦函数的分布从高斯分布和δ函数分布都变为均匀分布。

Study on Polarization Mode Dispersion Probability Distribution for Different Mode Coupling

The probability distribution of the differential group delay for different mode coupling is simulated with Monte-Carlo method. By fitting the results of the simulation, probability distribution function for different mode coupling is obtained. It is found that the probability distribution function of the magnitude of the dispersion changes from a very sharp δ-like function to Maxwellian with increase of coupling times of the two polarization modes. At certain coupling times, the probability distribution function is Gaussian. By taking two direction cosines of the polarization mode dispersion (PMD) vector for statistics, it is found that with increasing of the coupling times, the probability distribution of the direction cosines of the PMD vector changes from a Gassian and a δ-like distribution to a uniform distribution.