| 摘要 |
PURPOSE: To make an optical fiber coupler possible to be connected to two units of light sources for pumping and to make is possible to perform easy, safe and sure connection by forming a coupling part which consists of three optical fibers and where these fibers are fusion-stretched in parallel. CONSTITUTION: The coupling part which consists of the three optical fibers 11 to 13 and where these fibers are fusion-stretched in parallel is formed. Namely, the three optical fibers 11 to 13 are fixed to stretching bases 22, 23 with clamps 14, 15, and after the coating parts are removed, the fibers are heated with a burner 16 to form a fused part 21. This fused part is stretched by moving the stretching bases 22, 23 outward to form the optical fiber coupler. As regards this stretching, exit light rays 27 to 29 are received by photodetectors 18 to 20 by the stretching and are sensed by a monitor 30 when signal light 24 of a desired single wavelength, for example, a wavelength of 1.55μm, is made incident from a light emitting source 17 on the optical fiber 11 at about the symmetrical center. The quantities of the right rays received in the three optical fibers 11 to 13 change with the lapse of time. Then, the optical fiber coupler of which the branching ratio attains the desired value is obtd. if the stretching is stopped when the desired power ratio is attained. |
