| 摘要 |
PURPOSE:To obtain both a function for multiplexing and demultiplexing and a function for amplifying a light signal integrally by adding at least two kinds of rare earth elements which have absorption characteristics to the light source together in an optical fiber and propagating exciting light which has desired wavelength. CONSTITUTION:At least two kinds of rare earth elements which have absorptivity to the light signal 5 are added together to optical transmission paths 31 - 35 which constitute optical multiplexer demultiplexers 8 - 10 corresponding to the number of wavelengths of the light signal 5 and the exciting light 7 is propagated in the transmission lines. Namely, as the exciting light 7 is propagated in the optical transmission lines, the light is absorbed by at least two kinds of added rare earth elements and the energy potential is raised to a high level to generate an inverted distribution state. Consequently, when a light signal with corresponding wavelength is passed through a multiplexer demultiplexer, the signal is amplified by the inverted distribution and the light signal, multiplexed, demultiplexed, and outputted. |
