Patent ID: 7995921

Claim:
An apparatus comprising: an optical waveguide that supplies a first wavelength division multiplexed (WDM) signal, the first WDM signal including a plurality of first optical signals, each of which having a corresponding one of a plurality of wavelengths; a first coupler, coupled to the waveguide, having an input to receive the plurality of first optical signals and first and second outputs, the first output supplying a first portion of each of the plurality of first optical signals as a plurality of second optical signals, and the second output supplying a second portion of each of the plurality of optical signals as a plurality of third optical signals, each of the plurality of second optical signals having a corresponding one of the plurality of wavelengths and each of the plurality of third optical signals having a corresponding one of the plurality of wavelengths; a demultiplexer, coupled to the coupler, that receives the plurality of second optical signals from the first coupler, the demultiplexer having a first output and a second output, the first output of the demultiplexer supplying a first group of the plurality of second optical signals and the second output supplying a second group of the plurality of second optical signals; a first semiconductor optical amplifier (SOA) that selectively imparts a first gain over a C-band, each of the first group of the plurality of second optical signals having a corresponding wavelength within a first group of the plurality of wavelengths, the first group of the plurality of wavelengths being within the C-band, the first SOA supplying a first amplified group of the plurality of second optical signals; and a second SOA that selectively imparts a second gain over a an L-band, each of the second group of the plurality of second optical signals having a corresponding wavelength within a second group of the plurality of wavelengths, the second group of the plurality of wavelengths being within the L band, the second SOA supplying a second amplified group of the plurality of second optical signals; a multiplexer that receives the first and second amplified groups of the plurality of second optical signals, the multiplexer having an output, such that the first and second amplified groups of the plurality of second optical signals are combined at the output; and a second coupler, coupled to the multiplexer, the second coupler receiving the first and second amplified groups of the second plurality of optical signals and a fourth optical signal having a wavelength outside the first and second bands, the second coupler having an output that supplies a second WDM signal including the fourth optical signal and the first and second amplified groups of the plurality of second optical signals.