MONITORING DEVICE FOR OPTICAL FIBER SWITCH

PURPOSE:To confirm whether a switch itself in use is normal or abnormal, by mechanically interlocking optical fibers for monitoring fitted to optical fibers for an optical transmission line, and then monitoring their operation conditions. CONSTITUTION:An optical fiber main electrode 5 for monitoring is fitted to a main electrode 2 for an optical transmission line of an optical fiber switch 1 which change the connection states of an optical fiber cable 4, and an optical fiber slave electrode 6 for monitoring is fittd to the slave electrode 3, so that the main electrodes 2 and 5 perform the same operation. Under the light emission command of a light signal receiver 11, a power source 12 powers up an element 8. Then, about 50% of light transmitted through a semitransparent mirror 10 is sent as a monitoring signal to the main electrode 5 and passed through the gap of a coupling part to be photodetected by the slave electrode 6, so that it is sent to a photodetecting element 9. On the other hand, about 50% of light reflected is sent as a reference signal to another photodetecting element 9. They are converted into electric signals, which are passed through amplifiers 13 and compared 14, thereby outputting the coupling-state confirmation signal of the optical switch 1.