Connection structure between multi-core fiber and optical fiber bundle structure, connection structure between multi-core fibers, excitation method of rare-earth doped multicore fiber, and multi-core optical fiber amplifier

摘要

The optical fiber bundle structure 5 is connected to one end portion of the multi-core fiber 3 a. In the multi-core fiber, a tapered portion 27 is formed. In the tapered portion, the outer diameter and the core pitch of the multi-core fiber are reduced. Since the core pitch of the multi-core fiber can be increased on the side of the connection part with the optical fiber bundle structure, the optical fiber core wire 7a of the optical fiber bundle structure is provided with a large outer diameter, Excellent ones can be used. Further, when the other multi-core fiber 3 b is connected to the other end of the multi-core fiber, the outer diameters of the two multicore fibers 3 b can be made to coincide with each other, so that it is difficult for the core to be misaligned during fusion splicing.