Inhomogeneous profiles in re doped LaCl3 : satellites lines, energy transfer and up-conversion processes

Abstract
The technique of monochromatic excitation of the fluorescence has been applied to the 4I9/2 → 4G5/2 transition of Nd : (LaxPr1-x)Cl3. The variations of the emitted energy have been observed on reabsorbed transitions. This method has allowed the assignment of the different satellite lines to definite clusters of ions and the attribution of energy up-conversion to a cooperative process involving two identical interacting excited ions. This has led to an accurate analysis of the inhomogeneous absorption profile