| 摘要 |
PURPOSE:To improve the accuracy of the attenuator and, at the same time, to make the attenuator to be able to immediately cope with a secular change by providing an optical fiber for control separately from an optical fiber for attenuation and controlling the attenuation quantity of the optical fiber for attenuation by always monitoring the optical fiber for attenuation. CONSTITUTION:An optical fiber 7 for attenuation input is led to an input-side two-fiber section 9 together with an optical fiber 11 for control input led from a substrate 17 and fixed in the section in a state where the fiber 7 is integrally united with the fiber 11. Optical fibers 8 and 12 for attenuation output and control output are also constituted in the same manner. A controlled provided on the substrate 17 measures the power of light transmitted from an internal light source through the fibers 11 and 12 and realizes a prescribed attenuation quantity by controlling a moving device 16. Since this transmission route is the same as the route from an optical connector 2 for input to an optical connector 3 for output, an actual attenuation quantity can be controlled to a prescribed value by controlling the attenuation quantity to a desired level. Therefore, highly accurate control can be realized and any status change can be coped with accurately during operation, because the attenuation quantity is always monitored by leading the light for control to this attenuator. |
