Improving coherent atomic vapor optical buffers

We report on a theoretical study of the influence of incoherent optical pumping and beam profiling on slow light propagation in three-level atomic vapor. The pumping reduces the residual unwanted absorption of the signal while destroying the atomic coherence and increasing the group velocity of light. We show that the pumping enhances the resulting group delay for a certain range of parameters. We also examine changing the cross section of the beam of light along the propagation direction by, e.g., focusing the beam, for the purpose of maintaining the drive intensity to effectively counter its absorption.