Dependence of Judd-Ofelt parameters on overall changing factor of integrated absorption bands of Er3+.

Dependences of Judd-Ofelt (JO) intensity parameters Ω t (t = 2,4,6) and their relative ratios (Ω 4 /Ω 2 and Ω 6 /Ω 2) on overall changing factor (q) of integrated absorption bands of Er3+ have been studied theoretically. These dependences can help us to use relevant method to correctly extract Ω t of a powder material. The study was done by exemplifying the widely studied Er3+ system, which is doped into Gd 3 Ga 5 O 12 , LiNbO 3 and SrGdGa 3 O 7 bulk single-crystals and β-NaYF 4 crystalline powder. The results show that the Ω t changes linearly with the overall changing factor q : Ω t = γ t q + ξ t. The linear feature changes from one material to another. The magnetic-dipole oscillator of the 1.5 μm transition results in non-zero nodal increment ξ t and hence dramatical changes of the relative ratios Ω 4 /Ω 2 and Ω 6 /Ω 2 (with q) in smaller q region. The dramatical feature limits application of the relevant method for Ω t calibration of a luminescent powder. To get the precise Ω t values using the relevant method, the q value must be large enough. This can be realized by adopting a thin powder plate with a low Er3+ concentration for spectral measurement. • Ω t is studied against overall varying factor q of all Er3+ absorption band areas. • Ω t has a linear relation to q and the linear feature relies on the host material. • Ω 4 /Ω 2 and Ω 6 /Ω 2 change dramatically with the q parameter in smaller q region. • The feature is caused by magnetic-dipole oscillator of the 1.5 μm transition. • The change concerns validity of related method for Ω t calibration of a phosphor. [ABSTRACT FROM AUTHOR]