Optical link with reduced four-wave mixing

Abstract

An optical communication system and method of use thereof which uses dispersion compensators to intentionally create a dispersive condition at the output of subsequent inline optical amplifiers. The present invention reduces four-wave mixing and increases the allowable spacing between optical amplifiers, thus reducing the required number of amplifiers and dispersion compensators for a given length of optical fiber. In one embodiment, dispersion compensators and optical amplifiers are alternately spaced from one another along a length of an optical fiber such that the dispersion compensators render a dispersive condition at the amplifiers allowing each amplifier to be run at a higher power level. In another embodiment, the dispersion compensator is collocated with the amplifier, but is positioned between a pre-amp stage and a high power output stage to overcompensate both the slope and absolute dispersion of the fiber up to that point. The dispersion compensator provides a dispersive condition at the output of the output stage allowing the amplifier to be operated at a higher power level without creating four-wave mixing. In yet another embodiment of the invention, an additional dispersion compensator is provided at the output of a transmitter to overcompensate both the slope and absolute dispersion of the fiber to render a substantially neutral dispersion signal upon arrival at the next optical line element or receiver.