| 摘要 |
PURPOSE:To provide the optical fiber coupler consisting of single mode fibers varying in propagation constants usable in the case of optical connection of the single mode fibers varying in propagation constants with low connection loss like in the case of connection of, for example, a rare earth element-doped fiber and other single mode fibers and the method for producing the same. CONSTITUTION:This optical fiber coupler is formed by fusing and stretching two kinds of the single mode fibers f, fER varying in the propagation constants. The mode field diameters of both fibers are equalized and the clad diameters are reduced in the optical coupling region formed by fusing and stretching, by which the propagation constants of both fibers are made the same. |
