| 摘要 |
PURPOSE:To facilitate maintenance and to reduce the size of equipment for signal reception by disposing a light source for signals and a light source for excitation concentrically to a signal transmission side, propagating the light for exciting and the light for signals by an optical fiber to the signal reception side and distributing the light on the signal reception side, then optically amplifying the light. CONSTITUTION:A laser 4 for signal and laser 3 for excitation as a exciting source are disposed on the signal transmission side. The exciting light rays emitting the signal light amplified in a post amplifier 6 and the laser 3 for exciting are multiplied by means of multiplexer 5 and are integrally transmitted near to a subscriber's house by the optical fiber 2. The signal light and exciting light rays transmitted in the optical fiber 2 are distributed to the optical fibers 8 for plural subscribers's lines. Optical signal receivers 9 are respectively disposed at the terminals of the optical fibers 8 for the subscribers's lines and the optical fibers 1 for amplification doped with rare earth elements in the cores are connected to the intermediate points of the optical fibers 8 for the subscribers's lines. The maintenance is facilitated in this way and the equipment for signal reception is reduced in size. |
