SIGNAL TRANSMITTER USING OPTICAL PATH INCLUDING MONITOR SYSTEM FOR REPEATER

摘要

PROBLEM TO BE SOLVED: To disregard nearly disturbance caused by remote monitor modulation by selecting an optical wavelength spectral width of a remote monitor signal to be identical at least to a valid spectral width of a wavelength of a transmitted optical signal. SOLUTION: The system is a communication system between a main transmission reception management center 11 and a reception transmission center 12 by using an optical conductor 10. Repeaters 14-21 are provided to a main link 25 and branches 26, 27. An optical wavelength of each laser of transmitters 31-34 provided to the main center 11 has a spectral width of nearly 0.5nm and the laser beam is sent to an optical spectral region whose width is 10nm. Signals from the transmitters 31-34 are sent to an optical conductor 10 via a coupler 35. A remote monitor transmitter-receiver 50 is provided to the main center 11 for remote monitoring the repeaters 14-21. The transmitter-receiver 50 includes a transmitter 51 employing an optical diode. The optical wave carrying the remote monitor signal has at least a spectrum width of 10nm.