| 摘要 |
PURPOSE:To obtain an optical fiber with which the connection is eliminated to a special light attenuator, by irradiating the radiant rays to the optical fiber to denature the material of the optical fiber itself and then using the denaturated part as a light attenuating part. CONSTITUTION:A light source 2 is provided at an end of an optical fiber 1, and a photodetector 3 is set at the other end to detect the light intensity. A shielding plate 5 made of lead is set at a part of the fiber 1 where a light attenuating part 6 is formed, and radiant rays 8 are irradiated at the part 6 from a radiant ray generator 7 through a radiant ray irradiating aperture part. With this irradiation of radiant rays, a grid defect is generated to the material of the fiber 1 of the irradiated part. Thus the fiber 1 is colored or blackened to increase the transmission loss of light. The intensity of the light given from the light source 2 is monitored by a photodetector 3 while the radiant rays are irradiated. Then the irradiation of radiant rays is discontinued when the quantity of attenuation reaches a prescribed level. In such a way, the light attenuating part 6 having desired attenuating characteristics is formed at a desired part of the fiber 1. |
