Optical communication system, optical transmitting and receiving apparatus, and optical communication method

An optical communication system comprising:

• an optical switch that inputs, from a first port, an optical signal which has been transmitted by a first optical communication device and on which a main signal addressed to a second optical communication device and a control signal addressed to a destination different from the second optional communication device have been superimposed, and outputs the optical signal from a second port connected to a first optical transmission line included in an optical route in which an optical path between the first optical communication device and a second optical communication device is set;
• an optical brancher that branches a part of the optical signal which has been transmitted through the first optical transmission line, and outputs the branched optical signal to a second optical transmission line;
• and
• an optical transmitting and receiving apparatus that inputs the optical signal which has been branched by the optical brancher from the second optical transmission line,
• the optical transmitting and receiving apparatus including:
• a receiver that acquires the control signal from the optical signal which has been input from the second optical transmission line;
• a transmitter that generates an optical signal by use of light emitted by a light source;
• and
• a cutoff unit that prevents the light emitted by the light source from being input to the second optical transmission line.