| 摘要 |
PURPOSE:To obtain the optical fiber coupler which is usable over a wide wavelength band and can be manufactured at low cost with good reproducibility by using arraying members and selecting their refractive index properly. CONSTITUTION:Two optical fibers 1 and 2 are prepared first and the coating of their intermediate parts are partically removed. The arraying members 3 and 4 which have nearly the same refractive indexes with the clads and are slightly different in refractive index have half-divided receiving grooves 8 and 9 cut in their abutting surfaces 13 and 14 in such a shape that there is no gap formed when the optical fibers 1 and 2 are sandwiched and are fixed while the coating-removed optical fibers 1 and 2 are put in the receiving groove 8 and 9 so that the combination is maintained. In this state, they are heated all together to form the fusion-splicing part of the optical fibers 1 and 2. At this time, the arraying members 3 and 4 and the clads 11 and 12 of the optical fibers 1 and 2 are united. Then light is entered on one-terminal sides of the optical fibers 1 and 2 and projection light from the other-terminal sides if monitored; and the arraying members 3 and 4 are drawn until a desired branch ratio is obtained. |
