LINE MONITORING DEVICE FOR WAVELENGTH MULTIPLEX OPTICAL SUBMARINE CABLE NETWORK

摘要

PROBLEM TO BE SOLVED: To provide the line monitoring device which can monitor the wavelength multiplex optical submarine cable network. SOLUTION: An optical transmitter of a transmission-side terminal station device 1a of a station A receives a modulated signal from the line monitoring device 11, superposes it as a line monitor signal on a light signal, and outputs them to a repeating line. The line monitor signal which is sent back through the return line of each optical repeater inserted into the repeating line is demultiplexed by an optical coupler 23 and inputted to the line monitoring device 11. An optical selector 12 selects a feedback signal from each fiber couple. An array waveguide grating type filter 14 divides the selected wavelength multiple light signal into wavelengths λto λn and a selector 15 selects signals of the wavelengths, one by one. A photodetection part 16 performs photoelectric conversion and a demodulation part 17 demodulates the fed-back line monitor signal. A correlation part 18 checks whether or not there is abnormality in the line monitor signal to monitor whether or not trouble occurs to the repeating line. When the line monitoring of one fiber couple is completed, the line of a next fiber couple begins to be monitored.