Optical communication system with automatic gain control

An optical communication system formed by terminal stations, at least one optical repeater provided between terminal stations, and optical fiber cables connecting the terminal stations through said at least one optical repeater, said system comprising:

• an optical wavelength multiplexer provided in a first selected terminal station to multiplex a first optical signal having a wavelength (.lambda.1) with a second optical signal having a wavelength (.lambda.2);
• an optical wavelength demultiplexer provided in a second selected terminal station to demultiplex the first optical signal from the second optical signal;
• and
• wherein said at least one optical repeater has means for amplifying the first and second optical signals in accordance with a level of the second optical signal separated from the first optical signal.