Phase-Control of Photoabsorption in Optically Dense Media
  We present a self-consistent theory, as well as an illustrative application to a realistic system, of phase control of photoabsorption in an optically dense medium. We demonstrate that, when propagation effects are taken into consideration, the impact on phase control is significant. Independently of the value of the initial phase difference between the two fields, over a short scaled distance of propagation, the medium tends to settle the relative phase so that it cancels the atomic excitation. In addition, we find some rather unusual behavior for an optically thin layer. 
David Petrosyan and P. Lambropoulos