Patent ID: 7457546

Claim:
An optical transmission system comprising: (a) a transmitter that includes a pre-compensation fiber and transmits wavelength-division multiplexed (WDM) optical signals through the pre-compensation fiber; (b) a receiver that includes a post-compensation fiber and receives the WDM optical signals through the post-compensation fiber; (c) at least one optical repeater; and (d) an optical transmission line on which said at least one optical repeater is disposed, said optical transmission line being divided into a plurality of dispersion compensation intervals, wherein chromatic dispersion in said optical transmission line is managed in such a way that the dispersion compensation intervals have a non-zero net chromatic dispersion at every boundary point therebetween, or in such a way that the number of boundary points with zero net chromatic dispersion is reduced, wherein said optical transmission line is composed of a plurality of repeater sections separated by said at least one optical repeater; each dispersion compensation interval comprises: a main segment composed of a plurality of repeater sections with negative dispersion, and a compensation segment composed of a single repeater section with positive dispersion; and said dispersion compensation intervals have a non-uniform distribution of net chromatic dispersions by satisfying at least one condition selected from the group consisting of: the repeater sections have different average dispersions in absolute terms, the dispersion compensation intervals have different numbers of repeater sections in each dispersion is variable, and the repeater sections have different lengths; and the dispersion management is performed, wherein: the pre-compensation fiber in said transmitter that has no dispersion at the input end of the pre-compensation fiber and gives a non-zero dispersion to outgoing WDM optical signals, the WDM optical signals travel over said optical transmission line, their chromatic dispersions being compensated at intervals, so that the net dispersion will not become zero, and at said receiver, incoming WDM optical signals are directed to the post-compensation fiber to cancel out the dispersion accumulated so far.