| 摘要 |
PURPOSE:To prevent the radiation of light to adjacent optical waveguides by linearizing the part between the directional coupling part of the optical waveguides and a port. CONSTITUTION:A light source is connected to the port 31, an optical fiber to be measured is connected to the port 30 and a photodetector is connected to the port 32 in the case of application of this device to, for example, an optical switch to be used for a measuring instrument for measuring the breaking point of the optical fiber. The port 32 of such measuring instrument is an output terminal for signal light. The light is sent from the light source via the port 31 and the port 30 to the optical fiber to be measured. The return light from the optical fiber to be measured is then sent via the port 30 and the port 32 to the photodetector. Measurement is, thereupon, made to investigate the breaking point of the optical fiber to be measured. The part between the part 28 in proximity to the waveguides and the port 31 is linearized as mentioned above in such embodiment, by which the noises to the photodetector are decreased and the measurement with a high resolving power is enabled. |
