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1.
研究了能量接受离子Ce 3+对Er 3+上转换发光强度以及Er 3+在1.5μm附近波段发光性能参数的影响,并从能量匹配及能级结构角度出发对Er 3+/Ce 3+间的能量转移机制进行了分析.分析认为, 4I 11/2能级的Er 3+通过无辐射能量转移把能量传递给 2F 5/2能级的Ce 3+关键词:
氟磷酸盐玻璃
光谱性质
光纤放大器
3+和Ce 3+')" href="#">Er 3+和Ce 3+ 相似文献
2.
Yb3+:Er3+:Tm3+ co-doped borosilicate glasses are prepared.Their strong up-conversion photoluminescence spectra in a range from ultra-violet to near-infrared,which are excited by a 978-nm laser diode,are measured,and the mechanisms of energy transfer among Yb3+,Er3+ and Tm3+ ions are discussed.The results show that there is an unexpected wavelength at 900-nm emission from Yb3+ Stark splitting levels to pump Tm3+ ions and there exists an optimum pump power.The concentration of the Tm3+ dopant gives rise to a prominent effect on the intensity of visible and near-infrared emissions for the Yb3+:Er3+:Tm3+ co-doped borosilicate glasses. 相似文献
3.
Yb 3+ and Er 3+ co-doped YAB powders were prepared by sol-gel method. The structure and fluorescence properties were investigated. XRD pattern indicated that the single phase was obtained at 1150°C and the structure belonged to rhombohedral. Under 379 nm excitation, two emissions around 983 nm and 1531 nm were observed and the effect of Yb 3+ ion concentration on the emission intensity was discussed. The energy transfer was observed under 930 nm excitation and the energy transfer efficiencies for all samples were calculated. The lifetimes of 2 F 5/2 level of Yb 3+ ion and 4 I 13/2 level of Er 3+ ion were measured and the effect of Yb 3+ ion concentration on the lifetime was also discussed. The results indicated that there was an additional mechanism for the decay of 4 I 13/2 level in powder samples. The Yb 3+ and Er 3+ co-doped YAB powders should be a potential candidate for ceramic laser materials. 相似文献
4.
用高温熔融法制备了系列Er 3+/Yb 3+共掺,Ho 3+/Yb 3+共掺,和Er 3+/Yb 3+/Ho 3+三掺碲酸盐玻璃,在975nm激光抽运下三种掺杂玻璃中都出现了较强的绿光和红光上转换.研究了Yb 3+离子对Er 3+和Ho 3+离子上转换发光强度的影响以及Yb 3+→Er 关键词:
3+/Yb3+/Ho3+共掺')" href="#">Er3+/Yb3+/Ho3+共掺
碲酸盐玻璃
光谱性质
上转换 相似文献
5.
This paper reports that a series of Nd 3+:Er 3+:Yb 3+ co-doped borosilicate glasses have been prepared and their absorption spectra measured. The J--O intensity parameters Ωk ( k=2, 4, 6), spontaneous radiative lifetime τrad, spontaneous transition probability A, fluorescence branching ratio β and oscillator strength fed of the Nd 3+ ions at room temperature are calculated based on Judd--Ofelt (J--O) theory. The temperature dependence of the up-conversion photoluminescence characteristics in a Nd 3+:Er 3+:Yb 3+ co-doped sample is studied under a 978 nm semiconductor laser excitation, and the energy transfer mechanisms among Yb 3+, Er 3+ and Nd 3+ ions are analysed. The results show that the J--O intensity parameters Ω2 increase when the Nd 3+ concentration of the Nd 3+:Er 3+:Yb 3+ co-doped borosilicate glasses increases. The possibility of spontaneous transition is small and lifetimes are long at levels of 4F5/2 and 4F3/2. The intensity of Nd 3+ emissions at 595, 691, 753, 813 and 887 nm are markedly enhanced when the sample temperature exceeds 400 K. The reasons being the cooperation of the secondary sensitization from Er 3+ to Nd 3+ and the contribution of a multi-phonon. 相似文献
6.
采用化学共沉淀法制备了系列Y 1.98-2xYb 2x Er 0.02SiO 5(0.00≤ x≤0.15)以及Y 1.736Yb 0.24Er 0.02Tm 0.004SiO 5上转换发光材料,比较了室温下Y 1.98-2xYb 2x Er 0.02 SiO 5 ( x=0.00,0.08)样品在400—1600 nm范围内的吸收光谱,测量了所有样品在976 nm OPO激光器激发下的上转换发射光谱,以及Er 3+离子 4S3/2(4F9/2)→4I15/2,Tm 3+离子 1G4→3H6荧光衰减曲线和不同激发功率下的上转换蓝光发射强度,从而分析讨论了Er 3+,Tm 3+在Y 2SiO 5中的上转换发光机理.研究结果表明:在1250 ℃相对较低的温度下合成了X2型单斜晶系Y 2SiO 5 ∶Ln 3+(Ln 3+=Er 3+,Yb 3+,Tm 3+),Yb 3+的敏化显著增强了样品在976 nm附近的吸收能力,并大幅度加宽了该处的吸收带.分析上转换发射光谱发现:上转换绿光和红光强度都随着Yb 3+浓度的增加先增强后减弱,但红光的猝灭浓度较高,归因于Er 3+→Yb 3+反向能量传递ETU4和Yb 3+→Er 3+正向能量传递ETU3过程的发生;上转换蓝光发射是三光子吸收过程,是通过Yb 3+,Tm 3+之间三次声子辅助的能量转移方式实现的.
关键词:
上转换
共沉淀
2SiO 5∶Er 3+')" href="#">Y 2SiO 5∶Er 3+
3+')" href="#">Yb 3+
3+')" href="#">Tm 3+ 相似文献
7.
The electron-excitation energy transfer between Er 3+ and Yb 3+ ions in Er,Yb:YAl 3(BO 3) 4 crystals has been investigated. Crystals with different concentrations of active ions have been grown, and their luminescence decay kinetics in the spectral range near 1 μm have been experimentally measured. The energy-transfer microparameters have been calculated. It is shown that, to correctly describe the energy transfer in Er,Yb:YAl 3(BO 3) 4 crystals, one must take into account the interactions of higher orders than dipole-dipole interactions. 相似文献
8.
The upconversion luminescence spectral intensity of Er 3+ in Er 3+ and Yb 3+ codoped ZnO nanocrystals with and without Li + are investigated. Yb 3+ ions as a tradition sensibilizer have efficient energy transfer processes from Yb 3+ ( 2F 5/2) to Er 3+ ( 4I 13/2, 4I 11/2, 4F 9/2), which lead to the increment of upconversion luminescence intensity. Following by adding Li + to the Er 3+ and Yb 3+ codoped ZnO nanocrystals, the upconversion intensity emitted by Er 3+ ions is found greatly enhanced. The enhancement is attributed to the distortion of the local field symmetry of Er 3+ ions, so increases various intra-4f transitions of Er 3+ ions. Both Yb 3+ and Li + can disperse Er 3+ ions in specimen, so reduced the interaction between neighboring Er 3+ ions. 相似文献
9.
The ZrO 2:Er 3+ codoped with Yb 3+ phosphor powders have been prepared by the urea combustion route. Formation of the compounds ZrO 2:Er 3+ and ZrO 2:Er 3+, Yb 3+ was confirmed by XRD. The frequency upconversion emissions in the green and red regions upon excitation with a CW diode laser at ~978 nm are reported. Codoping with Yb 3+ enhances the emission intensities of the triply ionized erbium in the green and red spectral regions by about ~130 and ~820 times respectively. The emission properties of the ZrO 2:Er 3+ phosphor powders are discussed on the basis of excited state absorption, energy transfer, and cross-relaxation energy transfer mechanisms. 相似文献
10.
Color controllable Er 3+/Yb 3+‐codoped La 2MoO 6 upconverting nanocrystals are successfully synthesized via a facile sol‐gel method. Under the irradiation of 980 nm light, the entire samples exhibit dazzling upconversion (UC) emissions arising from the intra‐4f transitions of Er 3+ ions and the UC emission intensity is strongly dependent on the Yb 3+ ion concentration. Moreover, by controlling the Yb 3+ ion concentration, the emission color is changed from green to yellow and finally to red as a result of the energy back transfer from Er 3+ to Yb 3+ ions, which is further verified by the theoretically discussion based on the steady‐state rate expressions. The optical thermometric properties of the prepared nanocrystals based on the ( 2H 11/2, 4S 3/2) thermally coupled levels of Er 3+ ions are systematically studied by analyzing the temperature‐dependent green UC emission spectra in the range of 303–663 K. The maximum sensor sensitivity of resultant nanocrystals is determined to be 0.0083 K −1 at 510 K. Furthermore, the emitting color of the synthesized nanocrystals relies on the temperature. In addition, the heating effect induced by the excitation pump power is also investigated and the host lattice temperature is enhanced from 319 to 404 K with raising the pump power from 159 to 757 mW. 相似文献
11.
Sensitization of the fluorescence of Er3+ in fluoride phosphate glass containing up to 20 mol% phosphates by codoping with Cr3+ and Yb3+ is shown. The low order of ligand field strength for Cr3+ (Dq/B=2.04) results in broad Cr3+ fluorescence overlapping the Yb3+ absorption. The electronic energy transfer efficiency approaches 100%. Deviations of donor decay from the Förster law are interpreted in terms of the inhomogeneously acceptor distribution. The electronic energy transfer efficiency of Yb3+ → Er3+ reaches a maximum value of 75% for glasses containing 20 mol% phosphates. The transfer is shown to be migrationally accelerated by means of GAF-LAF-FB theory. From Judd-Ofelt parameters a stimulated emission cross-section for the transition4I13/2 →4I15/2 of Er3+ of 6.2×10−20 cm2 is derived. The c.w. laser action of Er3+ by Cr3+ excitation and double-step energy transfer is shown. The output is tuned continuously from 1536 to 1596 nm. Flashlamp pumping is also shown. 相似文献
12.
Wide band gap Yb 3+ and Er 3+ codoped ZrO 2 nanocrystals have been synthesized by a modified sol-gel method. Under 967 nm excitation strong green and red upconversion emission is observed for several Er 3+ to Yb 3+ ions concentration ratios. A simple microscopic rate equation model is used to study the effects of non-radiative direct Yb 3+ to Er 3+ energy transfer processes on the visible and near infrared fluorescence decay trends of both Er 3+ and Yb 3+ ions. The microscopic rate equation model takes into account the crystalline phase as well as the size of nanocrystals. Nanocrystals phase and size were estimated from XRD patterns. The rate equation model succeeds to fit simultaneously all visible and near infrared fluorescence decay profiles. The dipole-dipole interaction parameters that drive the non-radiative energy transfer processes depend on doping concentration due to crystallite phase changes. In addition the non-radiative relaxation rate ( 4I11/2→ 4I13/2) is found to be greater than that estimated by the Judd-Ofelt parameters due to the action of surface impurities. Results suggest that non-radiative direct Yb 3+ to Er 3+ energy transfer processes in ZrO 2:Yb,Er are extremely efficient. 相似文献
13.
采用共沉淀法制备了纳米晶ZrO 2-Al 2O 3∶Er 3+发光粉体.所制备的粉体室温下具有Er3+离子特征荧光发射,主发射在绿光,其中位于547 nm、560 nm的绿光最强,并得出稀土离子与基质之间有能量传递.对不同煅烧温度下的样品研究表明:因不同温度下所制得的样品晶相不同.研究了纳米晶ZrO2-Al2O3∶Er3+及ZrO 2-Al 2O 3∶Er 3+/Yb 3+的上转换发光,并分析了上转换的跃迁机制.发现ZrO 2-Al 2O 3∶Er 3+的绿光为双光子过程,而ZrO 2-Al 2O 3∶Er 3+、Yb 3+的上转换光谱中,红光和绿光也为双光子过程,而极弱的蓝光为三光子过程.讨论了Er 3+的浓度猝灭现象.最适宜掺杂浓度的原子分数为2%(Er 3+/Zr 4+). 相似文献
14.
Using the technique of high-temperature melting, a new Er 3+/Yb 3+ co-doped fluorophosphate glass was prepared. The absorption and fluorescence spectra were investigated in depth. The effect of Er 3+ and Yb 3+ concentration on the spectroscopic properties of the glass sample was also discussed. According to the Judd-Ofelt theory, the oscillator strength was computed. The lifetime of 4I 13/2 level ( τm) of Er 3+ ions was 8.23 ms, and the full width at half maximum of the dominating emission peak was 68 nm at 1.53 τm. The large stimulated emission cross section of the Er 3+ was calculated by the McCumber theory. The spectroscopic properties of Er 3+ ion were compared with those in different glasses. The full width at half maximum and σe are larger than those of other glass hosts, indicating this studied glass may be a potentially useful candidate for high-gain erbium-doped fiber amplifier. 相似文献
15.
Luminescence regularities have been studied in new erbium/ytterbium materials based on glasses and glass ceramics of a magnesium-aluminosilicate
system containing nanoscale erbium/ytterbium zirconate titanate crystals with the pyrochlore structure. Lifetimes of Yb 3+ and Er 3+ ions in the 2 F 5/2 state and in the 4I 11/2 and 4I 13/2 states, respectively, and the efficiency of Yb 3+ → Er 3+ energy transfer have been evaluated. The identified spectral-luminescent characteristics of the studied glasses and glass
ceramics co-doped with erbium and ytterbium ions show that these materials are promising media for producing laser generation
in the spectral range around 1.5 μm. 相似文献
16.
Uniform Yb 3+ and Er 3+-codoped Y 2O 3 hollow microspheres were synthesized via urea co-precipitation using carbon spheres as templates. Intense red emission ( 4F 9/2→ 4I 15/2) and weak green emission ( 2H 11/2, 4S 3/2→ 4I 15/2) of Er 3+ were observed for the Yb 3+ and Er 3+-codoped Y 2O 3 hollow microspheres under 980 nm infrared excitation. The integrated intensity of visible emission and the ratio of red to green were found to be strongly dependent on the amount of carbon sphere templates and the concentration of Yb 3+ ions. The amount of carbon sphere templates also plays an important role in adjusting the size of crystallite. Multi-phonon relaxation resulted from the absorbents (OH − and CO 32−) on the surface of the crystallite, and efficient occur of energy transfer processes and cross-relaxation between Er 3+ and Yb 3+ are responsible for the enhancement of intensity ratio of red to green emission. Interestingly, for higher concentration of Yb 3+ ions, the green emission is assigned to a three-phonon process in Y 2O 3:Yb/Er hollow microspheres, which also could result in the increase of the red to green emission ratio. An explanation to account for these behaviors was presented. 相似文献
17.
YNbO 4:Bi 3+, Yb 3+ phosphor was prepared to study the quantum cutting process of converting one ultraviolet photon into two near-infrared photons. An intense near-infrared emission of Yb 3+: 2F 5/2 → 2F 7/2 around 1 μm was observed under the ultraviolet excitation belonging to the broadband absorption of the [NbO 4] 3- group and the Bi 3+ ion. The photoluminescence spectra and decay lifetime measurements indicate efficient energy transfer from Bi 3+ to Yb 3+ ions, which is attributed to be of a cooperative energy transfer mechanism. The YNbO 4:Bi 3+, Yb 3+ phosphor with optimized doping concentration may be applicable in improving the efficiency of silicon-based solar cells. 相似文献
18.
在Er 3+/Yb 3+共掺TeO 2-WO 3-ZnO玻璃中引入Ce 3+,研究了Ce 3+对Er 3+1.5μm发射性能及其上转换发光性能的影响。结果表明,随Ce 3+浓度的增加Er 3+1.5μm波段的荧光强度先增强后降低,优化的Ce 3+掺杂浓度在2.07×10 20/cm 3左右;1.5μm波段的荧光寿命则随Ce 3+浓度的增加有轻微降低,从3.4ms降到3.0ms,但Ce 3+浓度的增加对1.5μm波段的荧光半高宽基本无影响;Er 3+/Ce 3+间的交叉弛豫Er 3+( 4I 11/2)+Ce 3+( 2F 5/2)→Er 3+( 4I 13/2)+Ce 3+( 2F 7/2)使玻璃的上转换发光强度大大降低,但在过高的Ce 3+浓度下,Er 3+/Ce 3+间的另一交叉弛豫Er 3+( 4I 13/2)+Ce 3+( 2F 5/2)→Er 3+( 4I 15/2)+Ce 3+( 2F 7/2)则使Er 3+4I 13/2能级粒子数减少,导致1.5μm波段荧光强度和荧光寿命降低.
关键词:
碲钨酸盐玻璃
发光性能
3+离子')" href="#">Er 3+离子
3+离子')" href="#">Ce 3+离子
交叉弛豫 相似文献
19.
The results of investigations of luminescent radiations’ kinetic characteristics for LiNbO 3:Yb 3+-Er 3+, LiNbO 3:Er 3+, and LiNbO 3:Yb 3+ crystals under optical excitations at 532 nm and 1064 nm wavelengths are presented. The shapes and times of rise and damping
of luminescent signals at 550 nm, 980 nm and 1555 nm wavelengths under selective excitations in the impurity subsystem of
the investigated materials are determined. Comparison of the temporal characteristics of luminescent responses of LiNbO 3 crystals doped separately with Yb 3+ and Er 3+ ions with those of the LiNbO 3:Yb 3+-Er 3+ crystal allows identifying the contributions from different energy transfer processes of optical excitation taking place
in the impurity subsystem of the material. 相似文献
20.
Energy transfer has been studied from Er 3+ to Eu 3+ ions on excitation with NIR photons (796 and 980 nm) with and without Yb 3+ ions. It is found that in one case the presence of Yb 3+ enhances the fluorescence yield (980 nm excitation) whereas in the other case it quenches (796 nm excitation). Energy transfer from Er 3+ ion's levels 4S 3/2 and 2H 11/2 is verified by decay curve analysis in both the cases. The nature of interaction between the donor (Er) and the acceptor (Eu) ions is found to be dipole-dipole. The energy transfer parameters viz. transfer probability, critical distance etc. have been calculated. 相似文献
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