FUSION REINFORCEMENT SLEEVE

PROBLEM TO BE SOLVED: To provide a fusion reinforcement sleeve which does not require the insertion of fibers or optical fiber ribbons in advance of the fusion.SOLUTION: A fusion reinforcement sleeve 10, which reinforces the fusion part of optical fibers 1 or optical fiber ribbons 2 by covering it, is heat shrinkable and protrusions 10a are formed on both lateral edges of the peripheral surface of the sleeve. The perpendicular distance I between the two protrusions 10a is wider than a diameter D of the optical fibers 1 or a height H of the optical fiber ribbons 2 so that the fusion part of the optical fibers 1 or the optical fiber ribbons 2 can be inserted in the fusion reinforcement sleeve 10 after the fusion of the fibers or the ribbons.