NEODYMIUM-TO-ERBIUM NONRADIATIVE ENERGY-TRANSFER AND FAST INITIAL FLUORESCENCE DECAY OF THE F-4(3 2) STATE OF NEODYMIUM IN GARNET CRYSTALS/

Two measurements were performed of the fast initial fluorescence decay of the F-4(3/2) state of Nd3+, following pulsed excitation of the ion in two garnet crystals, (i) Nd(1%), Er(15%), Cr(1%):YAG and (ii) Nd(1 .5%), Er(20%):YSGG. The nature of the interaction between Nd3+ and Er3 + ions is analyzed with a Monte Carlo model for the nonradiative energ y transfer from Nd to Er. Our measurements and the Monte Carlo analysi s corroborate the presence of a submicrosecond fluorescence decay tran sient and the reported nature of the interaction that drives the energ y transfer, i.e., a mixture of electrostatic interactions (dipole-dipo le, dipole-quadrupole, and quadrupole-quadrupole) and an exchange inte raction. (C) 1997 Optical Society of America.