| 摘要 |
PURPOSE:To provide a bidirectional optical amplifier having no gain change with one transmission line configuration. CONSTITUTION:First and second amplifying routes made of Er-doped fibers 3 are provided, and a signal light input from a transmission line is amplified by the different routes according to its advancing direction. The light is switched by circulators 1, 4 provided at both sides of an amplifier. The one circulator introduces the light of one direction to be input from the line to the first route, and sends the light from the second route to the line. The other circulator introduces the light of the other direction to be input from the line to the second route and sends the signal from the first route to the line. |
