Fluorescence dynamics of YVO4:Tm3+, YVO4:Tm3+, Tb3+ and YVO4:Tm3+, Ho3+ crystals

The fluorescence dynamics of the 3H4 and 3F4 energy levels of Tm3+ in YVO4 single crystals codoped or not codoped with Tb3+ and Ho3+ ions was experimentally investigated and compared with classical energy-transfer models. In the YVO4:1% Tm3+ and YVO4:1% Tm3+, 1% Ho3+ crystals, the 3H4 state relaxes predominantly by internal cross-relaxation-type energy transfers, whereas in the YVO4:0.5% Tm3+, 1% Tb3+ and YVO4:1% Tm3+, 1% Tb3+ crystals the relaxation is dominated by direct energy transfers to the 7F1 state of the Tb3+ ions. In all of the codoped systems, strong energy transfers from the 3F4 state of the Tm3+ ions to the 7F1 and 5I7 states of the Tb3+ and Ho3+ codopants were evident. The electric dipole-electric dipole coupling parameter was evaluated for several cross-relaxation and direct-energy-transfer processes

Growth and fluorescence properties of Tm3+ doped YVO4 and Y2O3 single crystals

This work is focused on the growth and the analysis of the potentials of Tm3+ doped YVO4 and Y2O3 single crystals for diode-pumped laser emission around the 1.5 μm eye safe laser wavelength. Both systems show broad-band absorptions around 800 nm and large stimulated emission cross sections around. 1.5 μm. © 1997 Elsevier Science B.V

Optical spectroscopy, fluorescence dynamics and crystal-field analysis of Er3+ in YVO4

The polarized absorption spectra, emission spectra and fluorescence dynamics of Er3+ doped in YVO4 are presented and analyzed in detail. Judd-Ofelt theory is applied to the measured absorption data to calculate the radiative decay rates for the various transitions of Er3+ in YVO4. A comparison of the experimental fluorescence lifetimes and the calculated radiative transition rates is made. Thermalization of the 2H11/2 level from the lower-lying 4S3/2 is studied. Crystal-field analysis is performed that is based on a Hamiltonian of D2d point-group symmetry. A best-fit analysis is performed resulting in an rms deviation of 6.7 cm-1

Excited state dynamics and energy transfer processes in YVO4:Er3+ crystals

An extensive investigation of the fluorescence dynamics of the (2H11/2, 4S3/2), 4F9/2, 4I9/2, 4I11/2, and 4I13/2, states was carried out for 0.1%, 1%, 2.5%, and 10% Er3+ doped in YVO4. The decay profiles of the luminescence of the 4S3/2 level of Er3+ (1.0%) obey the Inokuti-Hirayama model for energy transfer for an electric dipole-electric dipole interaction in the absence of diffusion among the donors. From the analysis we were able to calculate the critical distance, R0, and it was found to be 5.7 Å: The dipole-dipole coupling parameter was estimated to be 2.9 × 10-51 m6 s-1 and compared well to other well known systems. © 1997 American Institute of Physics

LHPG and FLUX growth of various Nd:YVO4 single crystals: A comparative characterization

The growth of YVO4 single crystals was investigated by the Laser-Heated Pedestal Growth method (LHPG) and flux technique. Several crystal growth experiments using LHPG were performed to optimize growth conditions by varying the Y2O3 and V2O5 proportions of the starting powders, the growth atmosphere, the laser power, and the pulling rate. The crystals were characterized by X-ray diffraction (XRD), optical microscopy, energy dispersive X-ray (EDX) microprobe, chemical analysis, and Raman spectroscopy. © 1993 Elsevier Science Ltd

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