Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5402483 | Journal of Luminescence | 2010 | 6 Pages |
Abstract
The spectroscopic characteristics and fluorescence dynamics for Yb3+/Ho3+:NaY(WO4)2 crystal were investigated. The parameters of oscillator strengths, the spontaneous transition probabilities, the fluorescence branching ratios, the radiative lifetimes and the stimulated emission cross sections have been calculated based on Judd-Ofelt theory and Füchtbauer-Ladenburg method. The energy transfer efficiency from Yb3+ to Ho3+ was 65.85%. The green emission (530-570Â nm) corresponding to (5F4, 5S2)â5I8 transition, red emission (640-670Â nm) due to 5F5â5I8 transition and NIR emission (740-770Â nm) attributed to (5F4, 5S2)â5I7 transition were observed on 974Â nm excitation at room temperature. Under low pump power, the intensity of green light emission is weaker than that of the red light, while under high pump power, the case is on the contrary. The upconversion is based on the two-photon process either the energy transfer from Yb3+ ions or by the excited state absorption. The proposed mechanisms of upconversion emissions were provided.
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Xinyang Huang, Guofu Wang,