保偏光纤双折射分析及全光纤拍长测试方法比对研究

Birefringence Analysis of Polarization Maintaining Fiber and Research on Characteristic of All-Fiber Beat-Length Experimental Systems

理论分析了保偏光纤双折射效应,应用有限元法建立了保偏光纤的三维模型,得到了其横截面上的应力分布及归一化的双折射参数。选择3种全光纤构成的纯光学系统进行对比拍长测试实验,实验结果和理论模型计算结果十分吻合,并对比研究了几种测试方法的优缺点。选定一种光路结构简单有效的双折射测试系统,对高双折射光子晶体光纤进行测试,测得了其归一化的双折射参数,并计算得其拍长约为1.2mm。研究结果对不同复杂结构保偏光纤的建模理论分析和拍长性能测试及高双折射光子晶体光纤设计制作后的性能测试有一定的实用价值。

The principle of polarization maintaining fiber （PMF） is analyzed and a three-dimensional model is established by utilizing the finite element method （FEM）. The stress distribution and normalized birefringence are obtained through this model. Three pure-optical beat-length measuring systems are carried out for contrastive research and the advantages and disadvantages are described. Experimental results are in good agreement with the theoretical results. Then one simple and effective method to test the beat-length of high-birefringence photonic crystal fiber （Hi-Bi PCF） is chosen and the results indicate that its beat-length is about 1.2 mm. This research provides an effective theoretical method for the analysis of PMF and a convenient experimental system for the beat- length testing of complex structure PMF and Hi-Bi PCF.