Non-radiative energy transfer from Dy3+ → Ho3+ in calibo glass

Non-radiative energy transfer from optically excited Dy3+ to Ho3+ is studied in calibo glass. An experimental investigation is made to the nature of excited Dy3+ donors in presence of Ho3+ acceptors. The time dependence of luminescence decay following the pulsed excitation illustrates the transient behaviour, characteristic of diffusion-limited relaxation. The data are analysed to determine the probability for Dy3+ → Ho3+ energy transfer and the critical transfer distance for energy exchange. The results imply that the mechanism of donor-acceptor energy transfer is based on electric dipole-dipole interaction. The value of diffusion constant for dipole-dipole donor-donor interaction is also calculated. (author)