An accurate method for alignment of polarization-maintaining fiber with CCD micro-imaging system

Abstract

Polarization-Maintaining(PM) optical fiber connector is widely used in various kinds of optic fiber sensors and communication equipments. The alignment of PM fiber polarization axis with the orientation key axis is one of the most important factors determining the extinction ratio of the connector. In order to ensure high accurate alignment of these two axises, CCD micro-imaging system is employed to take the cross-section image of Panda PM fiber, the edge points of stress rods are extracted by sub-pixel edge detection algorithm based on Hessian matrix. Consequently, the automatic detection of the polarization axis and the accurate calculation of the angle θ between the two axises are realized. Experiment results indicate that the method, combining CCD micro-imaging system and an accurate calculation of the angle θ, is effective to improve the alignment precision, which can reach ±0.5°. The work lays the foundation for realizing the auto-manufacture of PM optical fiber connector.