| 摘要 |
PURPOSE:To realize simple constitution and provide an amplifying function, and to demultiplex the multiplexed signal light without any loss by providing an optical amplification part made of quartz glass to which a rare earth element is added at least one place, and connecting exciting light guide-in parts which guide exciting light in the optical amplification part. CONSTITUTION:Optical amplification parts 15a and 15b consist of erbium-added single-mode optical fibers formed by adding the rare earth element, e.g. erbium to single-mode optical fibers. The exciting light guide-in parts 14a and 14b multiplex the exciting light from an exciting light source with signal light beams after demultiplexing which are projected from signal light projection parts 13a and 13b and guide the multiplexed light beams to the optical amplification parts 15a and 15b. When the exciting light beams are guided in, the rare earth element is excited with the exciting light to generate excited amplification effect accordingly. Therefore, the signal light beams which are made incident on the optical amplification parts 15a and 15b are amplified through amplifying operation and loss due to propagation in a signal light demultiplexing circuit is compensated. Consequently, the wavelength-multiplexed signal light can be demultiplexed with the simple constitution. |
