| 摘要 |
PROBLEM TO BE SOLVED: To disclose a method of forming a fused coupling between two different kinds of single mode optical fibers in which core size and/or refractive index profile are mutually different. SOLUTION: One fiber is a standard step type communication fiber having a core diameter of 9μm and a numerical aperture(NA) of approximately 0.1, while the other fiber is a dispersion compensating fiber(DCF) with a multilayer refractive index profile having a small core diameter and a high NA with the upper limit of approximately 0.3. When these two optical fibers are fusion coupled, dispersion gradually changes in the axial direction in an impurity dispersion area, with proximity to coupling included. The core diameter of the communication fiber gradually increases in the dispersion area as the coupling progresses in the fibers. By the dispersion of various impurities of the second fiber, the refractive index profile optically converges with that of the dispersion step type communication fiber. |
