Patent ID: 7038840

Claim:
A discrete Raman amplifier system for amplifying optical signals, the discrete Raman amplifier system comprising: a Raman gain fiber span; a first wavelength selection system coupled to a first end of the Raman gain fiber span and configured to reflect a selected wavelength on the Raman gain fiber span; a second wavelength selection system coupled to a second end of the Raman gain fiber span and configured to reflect the selected wavelength on the Raman gain fiber span; and a circulator comprising a first port, a second port, and a third port, wherein the first port of the circulator is coupled to the second wavelength selection system; a pump system coupled to the second port of the circulator and configured to pump light on the Raman gain fiber span to amplify the selected wavelength, wherein the selected wavelength corresponds to a first Raman Stokes shift from the light; and an isolator coupled to the first wavelength selection system and configured to receive the optical signals; wherein the light pumped by the pump system and the first and second wavelength selection systems amplify the optical signals at a second Raman Stokes shift from the light to generate amplified optical signals from the third port of the circulator.