METHOD OF FUSION SPLICING A RIBBON OF THIN OPTICAL FIBRES

A method for batch fusion splicing of an optical fiber ribbon using a fusion machine (10), the method comprising: preparing the optical fiber ribbon (1) which includes: three or more of optical fibers (2) arranged in parallel and connecting portions (3) connecting adjacent two optical fibers (2) together, each of the optical fibers (2) having a bare glass optical fiber (6) covered by a cover layer (7, 8), the connecting portions (3) being intermittently provided in each of a ribbon longitudinal direction; removing the cover layers (7, 8) so as to obtain the bare glass optical fibers (6); and placing the respective bare glass optical fibers (6) on V-shaped grooves (9) in the fusion machine (10), wherein the V-shaped grooves (9) are arranged in parallel with a pitch of 250 µm, each outer diameter dimension of the optical fibers (2) is set to smaller than or equal to 220 µm, and each distance between centers of the adjacent two optical fibers (2) is set to 250 µm with a margin of plus or minus 30 µm by each of the connecting portions (3).