Optical add/drop multiplexer node device

摘要

There is described an optical add/drop multiplexer node device capable of preventing leakage of information to another node in the event of occurrence of a failure in an optical add/drop circuit and establishing a highly reliable network. The optical add/drop multiplexer node device including a demultiplexer for dividing, according to wavelength, a wavelength-multiplexed optical signal which has been transmitted over an optical transmission path; a drop optical switch which receives at its input port optical signals of respective wavelengths divided by the demultiplexer; an add optical switch which has a first input port connected to the first output port of the drop optical switch; an optical receiver for receiving the optical signal dropped by way of the second output port of the drop optical switch; an optical transmitter for supplying an optical signal to be added by way of the second input port of the add optical switch; a multiplexer for multiplexing the optical signals of wavelengths output from the output port of the add optical switch and for transmitting the thus-multiplexed optical signal to an optical transmission path; and a monitor and control section for individually controlling the drop optical switch and the add optical switch.