成缆效应和测试条件对光纤PMD的影响

The Influence of Cabling effect and Measurement Conditions on Polarization Mode Dispersion in Optical Fibers

本文在分析光纤状态改变对偏振模色散（ＰＭＤ）产生的两种机制——应变机制和耦合机制的基础上，研究了成缆效应和测试条件中的各种因素对光纤ＰＭＤ的影响，包括光纤的成缆、着色、扭绞、侧压、弯曲、变温、敷设等过程产生的影响及其规律。发现应变能使ＰＭＤ增大，而模式耦合则使ＰＭＤ减小。两种机制都呈现出对光纤固有ＰＭＤ水平的依赖性：对于固有ＰＭＤ水平较低的光纤，应变机制起主导作用；而对于固有ＰＭＤ水平较高的光纤，耦合机制起主导作用。

The changes in the state of optical fiber can cause two mechanism on polarization mode dispersion——the strain mechanism and the mode coupling mechanism. Based on the analysis of them, this paper studies the influence of various factors in cabling effect and measurement conditions on the fiber PMD, such as the procedures of cabling, colouring, twisting, side stress, bending, change of temperature, laying of cables and so on. We find out the strain can increase the value of fiber PMD, while the mode coupling behaves by contraries. Moreover, both of these two mechanism appear some dependence on the intrinsic PMD of fibers. For the fibers with a low intrinsic PMD, the strain mechnism takes dominant effect, for the fibers with a high intrinsic PMD, the mode coupling mechnism takes dominant effect.