Nd3+→Yb3+ energy transfer in the YAl3(BO3)4 nonlinear laser crystal -: art. no. 035118

The main properties of the Nd3+-->Yb3+ (F-4(3/2), F-2(7/2) --> I-4(9/2), F-2(5/2)) energy transfer in yttrium aluminum borate nonlinear laser crystal have been studied. This host has been found especially suitable for efficient Nd3+-->Yb3+ energy transfer because of the good matching between phonon energy and the F-4(3/2)(Nd3+)-(2) F-7/2(Yb3+) energy gap (congruent to1000 cm(-1)). Energy-transfer probabilities in excess of 65% have been obtained for a Nd3+ (10 at.%) and Yb3+ (5 at. %) codoped sample. The influence of both crystal temperature and Nd3+ concentration on the transfer probability has been investigated. In the 15-350 K range the Nd3+ -->Yb3+ energy-transfer efficiency increases with temperature, whereas for crystal temperatures above 350 K the Nd3+ <-- Yb3+ back transfer is activated, leading to a decrease in the effective Nd3+ -->Yb3+ energy-transfer probability. The analysis of the decay curves obtained after pulsed excitation has been used to determine the multipole character of the Nd3+-Yb3+ interaction. The donor-acceptor energy-transfer microparameter was determined [C-DA(Nd3+-->Yb3+) congruent to 18 x 10(-39) cm(6)/s], and compared to those obtained for other Nd3+-Yb3+ co-doped materials.