RESONANT PULSE-PROPAGATION IN THE PRESENC E OF DIFFUSION EFFECTS

We present a study on the effects of the diffusion of the atomic inver sion in the coherent resonant pulse propagation. We present the soluti on of the corresponding Maxwell-Bloch equations obtained by a perturba tive technique based in the McCall and Hahn area theorem. The solution s correspond to a modification of the npi stationary trajectories of s uch a theorem. The new stability points depend on the radius of the fi eld wavefront and also on the diffusion coefficient. The McCall y Hahn 's results for the transversal averaged area of the same pulse in the presence of absorption are reproduced at the center of a gaussian wave front propagating in the presence of diffusion. The asintotic perfil a ccounts for the experimental results already explained using rate equa tions.