EVIDENCE OF ENERGY-TRANSFER AMONG ND IONS IN ND-YAG DRIVEN BY A MIXTURE OF EXCHANGE AND MULTIPOLAR INTERACTIONS

The non-radiative energy transfer between Nd ions in Nd:YAG is investi gated through high time-resolution fluorescence measurements of the F- 4(3/2) level of Nd. Our experimental data suggests that a strong short -range interaction, i.e., exchange interaction, contributes to the ene rgy transfer process between Nd ions at early times. In addition to it , our Monte Carlo simulations predict a multipolar mixture of interact ions, that is, dipole-dipole, dipole-quadrupole, quadrupole-quadrupole and exchange interactions. This result is compared with a similar mea surement and analysis for the Nd, Er, Cr:YAG luminescent system previo usly reported. (C) 1998 Published by Elsevier Science B.V. All rights reserved.