| 摘要 |
PURPOSE:To execute optical multiplexing of a high density and a low loss by making the most of the respective features of a star coupler and a wavelength multiplexer, by multiplexing light beams of plural contiguous wavelengths by a multiplexer having no wavelength dependency, and multiplexing plural multiplexed light beams by the wavelength multiplexer. CONSTITUTION:Light beams emitted from each signal source of wavelengths lambda1, lambda2, ...lambda10 are multiplexed by a star coupler 21, and light beams emitted from each signal source of wavelengths lambda11, lambda12, ...lambda20 are multiplexed by a star coupler 22. Light beams emitted from each signal source of wavelengths lambdan-9, lambdan-8, ...lambdan are multiplexed by a star coupler 2n/10, and n/10 pieces of multiplexed light beams are multiplexed by a wavelength multiplexer 3 and sent out of a transmission line 4. In this case, when the intensity of the light beam emitted from each signal source is '1', each signal light is attenuated to 1/10 by multiplexing of a star coupler 2 and sent to the wavelength multiplexer 3, and since there is no multiplexing loss therein, the intensity of the signal light is sent to the transmission line in a state that it remains in 1/10. In this way, a loss caused by multiplexing can be reduced. |
