| 摘要 |
PROBLEM TO BE SOLVED: To set transmission levels in a wavelength multiplex transmission to be high and in the same levels by providing at least two signal light sources having mutually different wavelengths, optical amplifiers arranged immediately after the signal light sources and a synthetic coupler synthesizing the outputs of the optical amplifiers. SOLUTION: Light sources 11-14 are laser diodes(LD) of the light sources, having the different wavelengths and the levels of the respective light sources are decided with current outputs injected from the outside. A rare-earth doped fiber amplifier, an optical fiber where erbium is added slightly to a core part and the optical fiber amplifier constituted of exciting LD which excites the optical fiber by the light signal of a 1.48μm or a 0.98μm band are used as the optical amplifiers 21-24. The output levels of the optical fiber amplifiers can be adjusted by the output power of exciting LD. The outputs of the optical amplifiers 21-24 are synthesized by a synthetic coupler 31 and is guided to one transmission line. |
