Yb3＋/Tm3＋ co-doped Gd3Ga5O12 single crystal with a dimension of Φ30mm×20mm was grown successfully by Czochralski method.The absorption spectrum was recorded at room temperature and used to calculate the absorp...Yb3＋/Tm3＋ co-doped Gd3Ga5O12 single crystal with a dimension of Φ30mm×20mm was grown successfully by Czochralski method.The absorption spectrum was recorded at room temperature and used to calculate the absorption cross-section.Based on the Judd-Ofelt（J-O） theory,we obtained the three intensity parameters and spectral parameters of this crystal,such as the line strengths,oscillator strengths,radiative probabilities and radiative lifetimes as well as the fluorescent branching ratios.Room temperature fluorescence spectra and luminescence decay curves were recorded.The energy transfer between Yb3＋-Tm3＋ was observed and the mechanism was discussed.The stimulated emission cross-section of the 3F4→3H6 transition was calculated by the Füchtbauer-Ladenburg（F-L） equation.The potential laser gains for this transition were also investigated.This crystal is promising as a tunable infrared laser crystal at 2.0 μm.展开更多
Tm3+/Yb3+ codoped NaYF4 microcrystals were synthesized using a hydrothermal method.The bright upconversion light was observed under 980 nm excitation.The upconversion luminescence was systematically investigated at di...Tm3+/Yb3+ codoped NaYF4 microcrystals were synthesized using a hydrothermal method.The bright upconversion light was observed under 980 nm excitation.The upconversion luminescence was systematically investigated at different Yb3+ concentrations and different reaction temperatures and time.The sample with 60% Yb3+ concentration and reacting at 180 oC for 24 h possessed the highest luminescent efficiency.The higher luminescent efficiency was contributed to a large surface area.The large surface area induced the large vibration mode by absorbed H2O and CO2.The larger vibration mode could enhance the energy transfer efficiency from the excited Yb3+ to Tm3+ by the process of phonon assisted energy transfer.展开更多
This research investigated the effect of different contents of Tm3＋ and different concentration ratios of Yb/Tm on the lumi- nescent properties of BaWO4：yb3＋/Tm3＋ nano-crystal synthesized by the hydrothermal metho...This research investigated the effect of different contents of Tm3＋ and different concentration ratios of Yb/Tm on the lumi- nescent properties of BaWO4：yb3＋/Tm3＋ nano-crystal synthesized by the hydrothermal method. The results indicated that lumines- cence intensity reached the strongest when CTm=1.0 mol.% and Cyb/CTm=2：1. X-ray diffraction revealed the tetragonal system of BaWO4：Yb3＋/Tm3＋ and the grain sizes were between 31 and 45 nm according to Scherrer equation. The results of X-ray diffraction and scanning electron microscopy were similar. Four emission peaks at 454, 475, 647 and 790 nm including two blue emission peaks and two red emission peaks, corresponding to ID2→3F4, 1G4→3H6, IG4→3F4 and 3H4→3H6 transitions of Tm3＋, were observed under excitation of 980 nm semiconductor laser. Blue emissions at 454 and 475 um were four-photon and three-photon absorption respec- tively in accordance with the relationship between luminescence intensity and pump power.展开更多
采用水热法制备了Yb^(3+)/Tm^(3+)共掺Y2(Mo O _4)_3系列上转换发光粉。由于Tm^(3+)在980nm附近没有吸收,单掺Tm^(3+)的样品观测不到任何发射。引入Yb^(3+)后,借助Yb^(3+)对980nm红外光的吸收和Yb^(3+)到Tm^(3+)的能量传递,在可将光区...采用水热法制备了Yb^(3+)/Tm^(3+)共掺Y2(Mo O _4)_3系列上转换发光粉。由于Tm^(3+)在980nm附近没有吸收,单掺Tm^(3+)的样品观测不到任何发射。引入Yb^(3+)后,借助Yb^(3+)对980nm红外光的吸收和Yb^(3+)到Tm^(3+)的能量传递,在可将光区观察到源自Tm^(3+)的蓝光和红光。这两个波段的发射随着Yb^(3+)和Tm^(3+)的浓度增加均呈现先增强后减弱的变化规律,8%和0.5%对应Yb^(3+)和Tm^(3+)的最佳掺杂浓度。上转换发射的功率关系研究表明,蓝、红光均为三光子过程,因此二者的产生过程为连续三步Yb^(3+)到Tm^(3+)的能量传递。展开更多
基金Supported by the Science & Technology Plan Project of Fujian Province (Nos 2005HZ1026 and 2007H0037)the Great Projects of FJIRSM (SZD08001-2 and SZD09001)the Open Science Foundation from Key Laboratory of Optoelectronic Materials Chemistry and Physics of CAS (No 2009KL004)
文摘Yb3＋/Tm3＋ co-doped Gd3Ga5O12 single crystal with a dimension of Φ30mm×20mm was grown successfully by Czochralski method.The absorption spectrum was recorded at room temperature and used to calculate the absorption cross-section.Based on the Judd-Ofelt（J-O） theory,we obtained the three intensity parameters and spectral parameters of this crystal,such as the line strengths,oscillator strengths,radiative probabilities and radiative lifetimes as well as the fluorescent branching ratios.Room temperature fluorescence spectra and luminescence decay curves were recorded.The energy transfer between Yb3＋-Tm3＋ was observed and the mechanism was discussed.The stimulated emission cross-section of the 3F4→3H6 transition was calculated by the Füchtbauer-Ladenburg（F-L） equation.The potential laser gains for this transition were also investigated.This crystal is promising as a tunable infrared laser crystal at 2.0 μm.
基金Project supported by the National Undergraduate Innovative Research Training Program and Natural Science Foundation of China (16874160)
文摘Tm3+/Yb3+ codoped NaYF4 microcrystals were synthesized using a hydrothermal method.The bright upconversion light was observed under 980 nm excitation.The upconversion luminescence was systematically investigated at different Yb3+ concentrations and different reaction temperatures and time.The sample with 60% Yb3+ concentration and reacting at 180 oC for 24 h possessed the highest luminescent efficiency.The higher luminescent efficiency was contributed to a large surface area.The large surface area induced the large vibration mode by absorbed H2O and CO2.The larger vibration mode could enhance the energy transfer efficiency from the excited Yb3+ to Tm3+ by the process of phonon assisted energy transfer.
基金supported by National Natural Science Foundation of China Youth Science (20901011)Jilin Science and Technology Bureau (20091510)
文摘This research investigated the effect of different contents of Tm3＋ and different concentration ratios of Yb/Tm on the lumi- nescent properties of BaWO4：yb3＋/Tm3＋ nano-crystal synthesized by the hydrothermal method. The results indicated that lumines- cence intensity reached the strongest when CTm=1.0 mol.% and Cyb/CTm=2：1. X-ray diffraction revealed the tetragonal system of BaWO4：Yb3＋/Tm3＋ and the grain sizes were between 31 and 45 nm according to Scherrer equation. The results of X-ray diffraction and scanning electron microscopy were similar. Four emission peaks at 454, 475, 647 and 790 nm including two blue emission peaks and two red emission peaks, corresponding to ID2→3F4, 1G4→3H6, IG4→3F4 and 3H4→3H6 transitions of Tm3＋, were observed under excitation of 980 nm semiconductor laser. Blue emissions at 454 and 475 um were four-photon and three-photon absorption respec- tively in accordance with the relationship between luminescence intensity and pump power.
文摘采用水热法制备了Yb^(3+)/Tm^(3+)共掺Y2(Mo O _4)_3系列上转换发光粉。由于Tm^(3+)在980nm附近没有吸收,单掺Tm^(3+)的样品观测不到任何发射。引入Yb^(3+)后,借助Yb^(3+)对980nm红外光的吸收和Yb^(3+)到Tm^(3+)的能量传递,在可将光区观察到源自Tm^(3+)的蓝光和红光。这两个波段的发射随着Yb^(3+)和Tm^(3+)的浓度增加均呈现先增强后减弱的变化规律,8%和0.5%对应Yb^(3+)和Tm^(3+)的最佳掺杂浓度。上转换发射的功率关系研究表明,蓝、红光均为三光子过程,因此二者的产生过程为连续三步Yb^(3+)到Tm^(3+)的能量传递。
