| 摘要 |
PURPOSE:To make stable mass production of optical coupling/branching devices by locally exerting large tension to a multifiber optical fiber for a short period of time in a stage of producing said fibers. CONSTITUTION:A base material 2 is heated to soften by a heater 3 and while said material is coated with a resin 4, tension is exerted thereto by a capstan 1 having projections and a belt 5 and the base material is drawn. Namely, the large tension is exerted locally to the multifiber optical fiber prior to curing by the projections by which said parts are elongated and diametrally reduced and respective cores 6 are brought near to each other. The optical coupling/ branching device is produced by elongating and diametrally reducing the multifiber optical fiber in such a manner and, therefore, the cores are uniformly brought in proximity to each other. The optical coupling/branching device having the excellent controllability of a branching ratio is produced with a small loss and good reproducibility and the mass productivity is improved. |
