| 摘要 |
PURPOSE:To reduce the variation of the optical signal due to the switch operation, by using an optical fiber each of a pair of the optical fibers having a smaller transmission loss of the optical signal and another pair having a larger transmission loss with two opposite pairs of optical fibers for an input and output terminal of a trunk line respectively. CONSTITUTION:Rod lenses 21-24 are provided to two opposite pairs of optical fibers A/C and B/D. When a switching mirror body 4 is up as shown in figure (a), the light emitted from an optical fiber A is reflected by the body 4 to be led to an optical fiber B. When the body 4 is down as shown in figure (b), the light is led to the fiber B from the fiber A to activate a light emitting element PD2 via a photodetector PD1. This emitted light is led to the fiber B from the fiber D. Then an optical fiber each of the pair having a smaller transmission loss and the pair having a larger transmission loss is used for an input and output terminal of a trunk line TL respectively. In such way, the variation of the optical signal due to the switch operation can be reduced. |
