| 摘要 |
PROBLEM TO BE SOLVED: To provide the protection structure for the optical coupler which can prevent the transmission loss of light from increasing as a protection structure for preventing an external flaw on a fiber core and also preventing dust, etc., from sticking. SOLUTION: Fiber core exposed parts 5A and 5B where fiber cores 3A and 3B are exposed are formed by peeling coating layers 4A and 4B at lengthwise intermediate parts of the optical fibers 2A and 2B. The fiber core exposed parts 5A and 5B are connected by fusion splicing to form a fusion splicing part and thus an optical coupler 1 is formed. While the fusion splicing part of the optical coupler 1 is put in a nearly cylindrical heat-shrinkable tube 50, both the end parts of the heat-shrinkable tube 50 are thermally shrunk to bring both the end parts of the heat-shrinkable tube 50 and the coating layers 4A and 4B at both the end sides of the fiber core exposed parts into contact with each other. |
