| 摘要 |
PURPOSE:To reduce an attenuation in transmission and thus increase the reliability, by installing a light branching device at a port part to control both the reflection factor and the transmission factor of the light to the incident light by the applied voltage. CONSTITUTION:The incident light supplied through a connector 11 of a port part 3 is branched to a light branching device 14a and a connector 11b through a light branching device 14. The light branched by the device 14a is transmitted to the next port part via a connector 11a. On the other hand, the light branched by the connector 11b is supplied to an application device 4, and the light sent from the device 4 is transmitted to the next port part via a connector 11c, the device 14a and the connector 11a each. The devices 14 and 14a can control the reflection factor of light by the applied voltage, and accordingly the reflection factor is usually set at 1. However, in case the device 4 has some fault, a switch 15 is changed over to set the reflection factor at 0. Then the light is transmitted to the next port part after by-passing the device 4. |
