Coherent pulse amplification in two-component media

The dynamics of pulse amplification in a medium containing two atomic components (one absorbing, one amplifying) is investigated in the regime in which the pulse interacts coherently with both components. It is shown that a pulse in this two-component medium may be amplified, absorbed, or broken up into a series of pulses, depending on the density of the absorbing species and the initial area of the pulse. Threshold values are determined for the impurity density and the area of the incident pulse. The possibility of pulse shortening during amplification is demonstrated.