Patent ID: 7768698

Claim:
A Raman amplifier operatively connected to an observation device, comprising: a pumping light source that outputs a pumping light that is intensity-modulated with a frequency higher than 100 megahertz; an optical coupler that couples the pumping light having a first propagation time with a carrier light having a second propagation time different than the first propagation time; and a Raman amplification medium that is pumped by the pumping light to amplify the carrier light, wherein the Raman amplification medium has dispersion properties configured to modulate the carrier light in the frequency higher than 100 megahertz of the pumping light source and wherein the difference between the first propagation time and the second propagation time is such that the Raman amplifier can achieve intensity modulation of higher than 100 megahertz, wherein the observation device generates an observation signal, and outputs the observation signal to the Raman amplification medium, and wherein the Raman amplification medium modulates the pumping light based on the observation signal, to output the modulated carrier light.