Recovering the propagation delay of an optical pulse

We present an experimental realization of an optical controlled fast light scheme that is able to achieve a recovering of an induced the delay experimented in propagation by a laser pulse after propagation in a slow-light medium. We show report a maximum induced advance in the fast light stage that completely recover the induced delay, thus canceling its the previous propagation history. These results are also of interest in the eld of a possible recover of delay in optical communication lines.