Optical module and optical communication system using an optical wavelength multiplexing and demultiplexing circuit and optical wavelength multiplexing and demultiplexing circuit

摘要

If you try to expand the transmission bandwidth in the synchronization of the AWG prior art, increase in loss of light transmission center frequency near inevitable. There is a limit to the bandwidth can be increased while ensuring the flatness of the transmission band, 0.5dB bandwidth of the transmission characteristics, was limited to 45% of the optical frequency channel spacing. Because of the limitations of this bandwidth, there is a problem that can not be applied to the synchronization AWG communication system, large-scale complex signal light passes through the point more. A synchronized AWG, an optical wavelength multiplexing and demultiplexing circuits of the present invention, an optical splitter which is installed in the interference in a circuit connected to the slab waveguide side to the other. Branching ratio of the optical splitter varies with the optical frequency, I take the minimum value in the transmission center optical frequency near the synchronization AWG. In the optical frequency some distance from the light transmission center frequency, it operates branching ratio is relatively large. It is preferable that the change period of the branching ratio in the optical splitter nest, is to half, or the same as the optical frequency of the synchronization channel spacing AWG.