| 摘要 |
An optical communication system in which transmission of information with a pumping light beam acting as the carrier, in addition to transmission of information with a signal light beam, is made possible is disclosed. This optical communication system includes an optical fiber amplifier adapted to amplify a signal light beam by having the signal light beam and a pumping light beam propagated through its rare-earth-doped fiber doped with a rare earth element and a modulating circuit for modulating the pumping light beam with a high-frequency modulating signal having a period shorter than the life span of fluorescence resulting from an excited state. In the case where the signal light beam and the pumping light beam are propagated in the same direction through the rare-earth-doped fiber, the transmission of information with the pumping light beam acting as the carrier can constitute a transmission of supervisory signal for an optical repeater, and in the case where the signal light beam and the pumping light beam are propagated in the directions opposite to each other through the rare-earth-doped fiber, a two-way transmission can be achieved by the transmission of information with the signal light beam and the transmission of information with the pumping light beam. |
