Patent ID: 6646788
Filing Date: 2003-11-11
Classification: H04B

Abstract:
A multi-stage optical amplifier, comprising:a first Raman amplifier stage operable to amplify a plurality of signal wavelengths, the first Raman stage having a gain profile wherein a majority of shorter signal wavelengths are amplified more than a majority of longer signal wavelengths; and a second Raman amplifier stage coupled to the first Raman amplifier stage and operable to amplify at least most of the plurality of signal wavelengths after those wavelengths have been amplified by the first stage, the second Raman stage having a gain profile wherein a majority of the longer signal wavelengths are amplified more than a majority of the shorter signal wavelengths; wherein an overall gain profile for the amplifier over the at least a portion of the plurality of signal wavelengths is approximately flat.