Linear concentration quenching of luminescence in rare earth laser materials

Assuming fast spatial energy diffusion among the donor ions, the rate equations are shown to yield the linear concentration dependence of the quenching rate observed in highly concentrated rare earth compounds, such as NdP₅O₁₄. This concentration dependence is not related to the particular form of the interionic interaction responsible for the quenching. We also supply new experimental data confirming the linear behavior in Nd_xRE_1?xP₅O₁₄ (RE = La, Eu, Tb) for 0.01 ? x ?1.