Method for fusion splicing of optical fibers

A fusion splicing method for splicing optical fibers, comprising:

• a fusion splicing process in which fusion splicing is performed by a butting end faces of two optical fibers together;
• and
• a heat treatment process in which the fusion spliced part of the optical
• fibers and the vicinity thereof are heated, wherein
• heating in the heat treatment process is performed using an arc heating unit having a pair of opposing arc electrodes, the fusion spliced optical fibers being placed therebetween;
• the heating center position of the arc electrodes being shifted by a relative movement with respect to the optical fibers in a direction other than the Y-axis direction, a direction perpendicular to both Z-axis direction and the opposing direction of arc electrodes, and Z-axis direction, the axial direction of the optical fibers, via the fusion spliced part in the Y-Z plane which is formed by the Z-axis direction and Y-axis direction.