Patent ID: 6542287
Filing Date: 2003-04-01
Classification: H01S,H04B

Abstract:
Raman pump equipment for a distributed Raman amplifier in a fiber-optic communications link having a span of transmission fiber, wherein the span of transmission fiber carries optical signals on channels at different wavelengths, wherein the optical signals include guaranteed signals that are always present when the communications link is operating normally, comprising:a Raman pump source that produces Raman pump light at a pump power that optically pumps the transmission fiber to produce Raman gain for the optical signals on the fiber; optical components and monitoring circuitry that measure the power of the guaranteed signals after the guaranteed signals pass through the transmission fiber; a control unit that controls the pump power of the Raman pump source based on the measured power of the guaranteed signals to suppress transients in the Raman gain; and optical monitoring equipment for monitoring the total power of the optical signals after the optical signals have been carried over the span of the transmission fiber, wherein the control unit is configured to control the pump power of the Raman pump source by using feedback control based on the measured power of the guaranteed signals and using feed-forward control based on the monitored total power of the optical signals.