PURPOSE: To prevent the generation of cracks due to destruction of array and to obtain an image fiber reduced at its optical leakage and having high transmission characteristics because of difference of core diameters by preparing ≥two kinds of many cores of which outer diameters are different with each other and drawing and aligning these cores in the longitudinal direction.
CONSTITUTION: Multicore fibers 11 or 13 are used as optical fiber strands and the inside of a tube 19 such as a quartz tube is tightly charged with the many strands to form strand-aggregated state and use the tubed strand aggregate as an image bese material. The base material is drawn with heat after collapsing the base material by heat or without passing through the collapsing process, so that image fibers unifying clads and having ≥ two kinds of core outer diameters are obtained. The multicore fibers 11 are provided with monocore fibers 12aW 12e and the fibers 13 are provided with monocore fibers 14aW14g.
SATOU TSUGIO
ISHIBASHI TOKIO
SHIBUYA SEIJI
