Patent ID: 7200333

Claim:
An optical communication apparatus for use with a wavelength division multiplexed (WDM) light signal that includes a plurality of signal transmission band lights multiplexed together and corresponding to a plurality of signal transmission bands, respectively, the apparatus comprising: a first optical unit receiving a respective signal transmission band light of the plurality of signal transmission band lights as the respective signal transmission band light is separate from the WDM light signal, providing distributed Raman amplification to the received signal transmission band light, and having a characteristic that compensates for dispersion of a transmission path to which said optical communication apparatus is connected, with respect to the signal transmission band corresponding to the received signal transmission band light, to thereby provide Raman amplification and dispersion compensation to the received signal transmission band light as the received signal transmission band light is separate from the WDM light signal; and a second optical unit receiving the WDM light signal, providing distributed Raman amplification to the received WDM light signal, and having a chromatic dispersion characteristic and a dispersion slope characteristic of reverse signs relative to the transmission path with respect to a predetermined signal transmission band of the plurality of signal transmission bands, to thereby provide Raman amplification and dispersion compensation to the WDM signal light, wherein the first optical unit compensates for residual dispersion in the respective signal transmission band light received by the first optical unit that remains after the dispersion compensation provided to the WDM signal light by the second optical unit.