| 摘要 |
PURPOSE:To realize an economical optical fiber relay system by providing an optical directional coupler to the system and superposing optically a signal light of the coherent optical communication system and a signal light of the optical intensity modulation signal and relaying the resulting light through a same optical fiber. CONSTITUTION:The coherent optical communication system 2 and the optical intensity modulation system 3 of a sender side terminal station 1 are coupled by an optical directional coupler 4 and output a signal light through an optical fiber 5. An optical directional coupler 7 of a receiver side terminal station 6 branches the signal light outputted from the coherent optical communication system 2 and the optical intensity modulation system 3 and the result is inputted to a coherent optical communication system 8 and an optical intensity modulation system 9 of the receiver side terminal station 6. Thus, the signal light of the coherent optical communication system and the signal light of the optical intensity modulation signal are superposed optically and the relay system employing a same optical fiber is attained and the economical optical fiber relay system is realized. |
