Patent ID: 6775056
Filing Date: 2004-08-10
Classification: H01S,H04B

Abstract:
An optical transmission system comprising:a plurality of optical processing nodes configured to optically communicate via optical signals in a signal wavelength range; and, a plurality of signal varying devices positioned to vary an optical signal passing between the processing nodes, wherein the plurality of signal varying devices includes: a first signal varying device at a first location including optical fiber provided with optical energy in a first set of pump wavelengths from a first pump source to produce Raman gain having a first signal variation profile in the optical signals over the signal wavelength range, wherein the optical fiber is configured to produce Raman gain in a signal wavelength range and provide concentrated amplification, attenuation, and lossless transmission in the optical fiber, and the first pump source is configured to provide pump energy to the optical fiber in a plurality of pump wavelengths having sufficient pump energy to produce Raman gain and a signal variation profile in the signal wavelength range and the pump source is further configured to control the pump energy in at least one of the pump wavelengths to vary the signal variation profile and provide amplification, attenuation, and lossless transmission in the optical fiber over the signal wavelength range; and a second signal varying device at a second location remote from the first location and configured to provide a second signal variation profile over the signal wavelength range, wherein the first and second signal variation profiles provide for a cumulative signal variation profile over the signal wavelength range that differs from either of the first and second signal variation profiles.