| 摘要 |
PROBLEM TO BE SOLVED: To provide a method capable of connecting with a low loss, two optical fibers largely different in electromagnetic field distribution. SOLUTION: In this connection method, when a first optical fiber having a refractive index distribution shape close to the Gaussian distribution is connected to a second optical fiber comprising a core 13 consisting of at least two layers comprising a central part (central core part 11) with a refractive index lower than a clad 14 and a peripheral part (peripheral core part 12) with the highest refractive index and having an effective core sectional area in a using wavelength >=80μm2, a third optical fiber having a refractive index distribution shape close to the second optical fiber and an effective core sectional area in the using wavelength smaller than the second optical fiber is inserted. |
