OPTICAL BRANCHING DEVICE

摘要

PURPOSE:To ensure the reliability of an optical loop line network by connecting each one port at both ends of a 4 port optical directional coupler to a device in the optical loop line network and connecting other 4-port optical directional coupler to other idle two output ports respectively. CONSTITUTION:A video signal sent from a head end 7 is sent in two-way in an optical loop line network 8. A 4-port optical directional coupler 9a integrated in the optical loop line network 8 branches left and right turns and 4-port optical directional couplers 9b, 9b are connected to the output ports respectively to obtain two sets each of right turn signals 9c and left turn signals 9d. One set of the right turn signals 9c among them is given to an optical switch 10 to be used for changeover control at a broken optical loop network, then the fault is momentarily restored. Or a wavelength multiplex coupler 11 is employed to be configurated in common use of active / standby lines in the communication system.