| 摘要 |
PURPOSE:To easily control the fusion width of optical fibers by forming the optical fibers in such a manner that at least one thereof is provided with a jacket layer which has the same quality as the quality of a clad layer and has the softening point temp. lower than the softening point temp. of the clad layer. CONSTITUTION:Quartz glass of the same quality is used for the respective cores 2a, 3a and clad layers 2b, 2b of a 1st optical fiber 2 and a 2nd optical fiber 3 and the jacket layer 2c of the 1st optical fiber 2. The jacket layer 2c is constituted of the quartz glass having the softening temp. lower than the softening temp. of the clad layer 2b. The fusion of the optical fibers is, therefore, completed by softening and deforming (nearly melting) of only the jacket 2c and the jacket layer 2c has the same quality as the quality of the clad layer 2b and, therefore, the fusion width is the width including the width of the jacket layer 2c and is prevented from increasing to a specified value by the thickness of the jacket layer 2c. Thus, the desired fusion width is attained when the thickness of the jacket layer 2c is previously adjusted. |
