| 摘要 |
<P>PROBLEM TO BE SOLVED: To avoid an effect on the gain setting of a preamplifier at the time of startup, caused by the insertion of an interleaver in a wavelength division multiplex communications system that includes an OADM node. <P>SOLUTION: Each of a plurality of OADM nodes includes a first interleaver for dividing an wavelength-multiplexed optical signal into a wavelength of odd number and a wavelength of even number, and a first and a second systems provided, corresponding to the optical signal in the wavelength group of the odd number and the wavelength group of the even number divided by the interleaver and output therefrom. Each of the first and the second systems includes a preamplifier, a wavelength-multiplexing divider, a branch insertion section and a postamplifier. Further, there are provided a second interleaver for synthesizing the outputs of the postamplifiers in the first and second systems. At the time of the startup, the level of ASE light fed from the postamplifier in an OADM node of a former stage is set large, corresponding to the difference between an input level of the first interleaver of the OADM node on a latter stage and a predetermined gain of the preamplifier. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
