O. Guillot-noel et al., Spectroscopic evidence of inhomogeneous distribution of Nd3+ in YVO4, YPO4and YAsO4 crystals, OPT MATER, 13(4), 2000, pp. 427-437
Nd3+:YVO4 is one of the most interesting laser hosts for micro and diode-pu
mped solid state lasers. We have studied magnetic and optical properties of
Nd3+ in three zircon type crystals YMO4 (M = V, As, P). In particular, Nd3
+ ions exhibit in the three hosts a multisite character observed in the abs
orption and emission spectra. However, the emission and its dynamics are st
rongly dependant on the reabsorption mechanisms. In Nd:YVO4, single crystal
s containing 7 +/- 1 x 10(18) Nd3+ ions/cm(3), the lifetime is 95 +/- 2 mu
s in good agreement with the calculated radiative lifetime. Electron Parama
gnetic Resonance (EPR) measurements are performed to identify the nature of
the different substitution sites for Nd3+ ions. Nd3+ ions are found to be
inhomogeneously distributed in tetragonal D-2d symmetry sites, in isolated
ions, "shallow clusters" and pairs. Proportions of the different local envi
ronments depend on the total neodymium concentration. For instance, 15% of
the Nd3+ ions are gathered in Nd3+-Nd3+ pairs for 7.2 +/- 0.2 x 10(19) Nd3 ions/cm3. (C) 2000 Elsevier Science B.V.. All rights reserved.