双尾纤相对位置的装配精度直接影响保偏双光纤准直器的保偏性能。研究和分析了双尾纤的装配精度对保偏准直器保偏性能的影响，并指出双尾纤端面“猫眼”的垂直度是主要影响因素。提出了一种保偏双尾纤装配精度的检测方法，检测系统主要由CCD摄像机、显微镜、图像采集卡和VC开发的检测处理软件等构成。还对系统中保偏双尾纤端面图像获取及图像预处理、检测光心“猫眼”坐标位置所采用的算法及“猫眼”垂直度的检测模型进行阐述，该系统检测精度优于0．5°。

The assemble precision of relative position of the dual-fiber directly affects performance of collimator of polarization maintaining optical fiber. The impact of the packaging accuracy of polarization maintaining optical fiber on capability of the polarization-maintaining collimator is researched and analyzed. Especially it indicated that the “cat eyes” perpendicular degree of the dual pigtail is main factor. A method on measuring assemble precision for polarization maintaining optical fiber is put forward. The main parts of the system are CCD camera,microscope,image board and image processing software developed with VC + + . The method how to obtain image of end of polarization maintaining optical fiber,the algorithm which includes image pre-processing,how to detect the coordinate position of “cat eyes” and mathematical model for computing verticality of two slow axes of “cat eyes” are explained. The experimental results show its resolution of the small angle measurement is better than 0.5°