| 摘要 |
PURPOSE:To provide the optical fiber which allows easy handling, is highly mechanically strong and tough, is highly resistant to temp. and can stably maintain a light transmission loss by bending the optical fiber consisting of a specific fiber and a specific protective layer to <=42mm curl diameter. CONSTITUTION:The above cord consists of a bare cord 1a constituted of the fiber 2 and the transparent protective layer 3 having the refractive index smaller by >=0.01 than the refractive index of the fiber 2 or further a coated cord 1b constituted to have one or more layers of coating layers 4 as a protective layer on the outer layer of the protective layer 3. The fiber 2 consists of a polycarbonate resin and the kinds of the resins constituting the protective layer 3 include polymethyl methacrylate, poly-4-methyl pentene-1, etc. At least a part thereof or preferably the main part thereof is subjected to the bending in such a manner that the curl diameter attains <=42mm. The optical fiber which allows easy handling, is highly mechanically strong and tough, is highly resistant to temp. and can stably maintain the low light transmission loss in spite of use particularly at a relatively high temp. is obtd. in this way. |
