Self-advanced fast light propagation in an optical fiber based on Brillouin scattering

We experimentally demonstrate an extremely simple technique to achieve pulse advancements in optical fibers by using both spontaneous amplified and stimulated Brillouin scattering. It is shown that the group velocity of a light signal is all-optically controlled by its average power while it propagates through an optical fiber. The signal generates an intense back-propagating Stokes emission that causes a loss on the signal through depletion. This narrowband loss gives rise to a fast light propagation at the exact signal frequency. The Stokes emission self-adapts in real time to the Brillouin properties of the fiber and to a wide extent to the signal bandwidth.