METHOD AND APPARATUS FOR TWO-WAY OPTICAL COMMUNICATION

摘要

PURPOSE:To realize the transmission with high efficiency, low cost and long range by sending an optical signal of a wavelength lambda1 from a station A while amplifying the signal through a rare-earth element additive optical transmission line and sending information at a station B while multiplexing the information on an optical signal in a wavelength lambda1 to stimulate the rare-earth element additive optical transmission line. CONSTITUTION:An optical transmission section 1 of a station 8 consists of a light emitting element 10 sending an optical signal of a wavelength Al and a rare-earth element additive optical transmission line 15 to amplify the said optical signal. An optical transmission section 5 of a station 10 consists of a light emitting element (wavelength lambda1) to stimulate the said rare-earth element additive optical transmission line 15, an information signal is multiplexed on the optical signal and the resulting signal is sent to the station 8 via an optical multiplexer/demultiplexer section 7 and an optical fiber 4. Then the signal is demultiplexed by an optical demultiplexer section 16, the part of the signal is fed to an optical reception section 2, in which the information signal is reproduced. Most of the remaining signal is subject to amplification of the optical signal whose wavelength is lambda1 through the propagation in the rare-earth element additive optical transmission line 15. Moreover, the information signal is multiplexed on even the optical signal whose wavelength is lambda1.