| 摘要 |
PURPOSE:To achieve low-noise and high-gain repeating by transmitting coherent light after frequency modulation by a signal, receiving it through an optical isolator at a repeater, and transmitting the received light after the optical amplification of an application synchronous optical amplifier. CONSTITUTION:An optical signal transmission part 1 generates an FSK signal by a coherent single longitudinal-mode laser, and this optical signal is inputted to an optical repeater 3 through a single mode fiber 2. At the repeater 3, the optical signal is inputted to an application synchronous optical amplifier 5 made of a semiconductor laser through an optical isolator 4 which cuts off reflected light to the transmission part 1 and light from the amplifier 5. The FSK optical signal amplified by the amplifier 5 is inputted again to a single-mode fiber 2 and reaches a coherent optical reception part 6 through the repeater 3. A reception part 6 employs an optical heterodyne system to achieve optical transmission which has a wide band and a long repeating interval. |
