End face image self-correlation based optical fiber polarization-maintaining fusion-welding rotation angle alignment method

The invention discloses an end face image self-correlation based optical fiber polarization-maintaining fusion-welding rotation angle alignment method. The method comprises the steps that images of two sections of optical fiber end faces are obtained through an end face imaging device of a fusion-welding machine, and the images of optical fiber end face zones are extracted by using an edge detection and circle fitting method; the frequency components on horizontal section lines are compared by calculating self-correlation coefficients at different angles to complete rotation angle alignment of two sections of optical fiber end faces. The end face image self-correlation based optical fiber polarization-maintaining fusion-welding rotation angle alignment method is suitable for optical fibers needing polarization-maintaining fusion-welding, for example, panda type polarization-maintaining optical fibers and multi-core optical fibers, can also perform fusion welding of different types of two-section optical fiber