| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical transmission system which is excellent in the use efficiency of an optical frequency and is easy to change. <P>SOLUTION: Respective optical frequencies of signal light of a multiwavelength which has been propagated on an optical fiber transmission line 2 and is inputted to an input port of an optical demultiplexer 3 are disposed at positions of a fixed interval Δf. The arrangement of the optical frequency of each signal light which is demultiplexed from each output port of the optical demultiplexer 3 and outputted to an optical amplifier 4<SB>m</SB>has a fixed cycle NΔf. In this case, N is an integer ≥2. When respective optical frequencies of three beams of optional signal light satisfying the following condition: f<SB>a</SB><f<SB>b</SB><f<SB>d</SB>, and f<SB>d</SB>-f<SB>a</SB>≤NΔf among respective beams of the signal light which are demultiplexed from each output port of the optical demultiplexer 3 and outputted to the optical amplifier 4<SB>m</SB>are defined as f<SB>a</SB>, f<SB>b</SB>, f<SB>d</SB>, these optical frequencies satisfy the following relational expression: 2f<SB>b</SB>≠f<SB>a</SB>+f<SB>d</SB>. <P>COPYRIGHT: (C)2004,JPO |
