Er3+/Tm3+/Yb3+共掺氟氧化物玻璃的上转换白光性质

采用高温固相法制备了Er3+/Yb3+、Tm3+/Yb3+和Er3+/Tm3+/Yb3+共掺杂的氟氧化物玻璃SiO2-Al2O3-Na2O-ZnF2,研究了980nm近红外激光激发下的上转换发光性质。研究表明,Er3+/Yb3+共掺样品呈现了上转换绿光和红光发射,Tm3+/Yb3+共掺样品呈现了强的上转换蓝光发射和弱的红光发射,Er3+/Tm3+/Yb3+三掺样品呈现了上转换白光发射。对上转换发光强度和激光功率的研究表明上转换绿光和红光发射是两光子吸收过程,上转换蓝光发射是三光子吸收过程。     

Zn2+掺杂NaAlSiO4:Er3+,Yb3+微晶玻璃制备及上转换发光性能

主要研究过渡金属Zn2+离子掺杂对NaAlSiO4:Er3+,Yb3+微晶玻璃上转换发光性能的影响.采用高温熔融法制备不同掺杂浓度的Zn2+掺杂NaAlSiO4:Er3+,Yb3+上转换发光样品,通过同步热分析仪(DSC)、X射线衍射仪(XRD)、傅里叶红外光谱仪和荧光光谱分析仪等对样品进行热处理制度、析出晶体、玻璃结...     

Er3+离子掺杂透明的LaF3-SiO2纳米玻璃-陶瓷的上转换发光

采用溶胶-凝胶法成功制备了一系列Er3 掺杂的透明纳米LaF3-SiO2玻璃-陶瓷样品,并研究了其上转换发光性质与发光机制.研究得到了Er3 浓度对上转换发光的影响规律,拟合了上转换荧光强度与LD工作电流的关系,发现所得结果与理论值能够很好地一致.在980nm激光二极管激发下,获得了发射波长为520、540、660nm的有效上转换发光.在较低的功率泵浦下,540nm波长的绿光波段发射最强,其发光主要过程是处于4F7/2态的Er3 离子能量大部分被弛豫到4S3/2态,再由此激发态跃迁到基态4I15/2态所致.     

Er3+/Yb3+共掺Al2O3光波导放大器的成分优化

利用980 nm泵浦光激发下Er3+/Yb3+共掺Al2O3光波导放大器的粒子数速率方程,研究了稀土离子掺杂浓度对Er3+/Yb3+共掺Al2O3光波导放大器光学增益的影响.在此模型中,充分考虑到受激吸收、受激发射、自发辐射、能量转移等过程,揭示了稀土离子掺杂浓度和光学增益之间的紧密关系.结果表明,适量Yb3+的共掺杂能够显著提高Al2O3光波导放大器的光学增益.光波导放大器中Er3+/Yb3+的最佳共掺杂浓度不是固定值,受到泵浦功率、光波导放大器长度等因素影响,揭示了各有关报道中最佳掺杂浓度结果不一致的原因.     

Er~(3+)/Yb~(3+)共掺SrF_2纳米晶的溶剂热合成及发光性能研究

采用溶剂热方法制备得到了Er3+和Yb3+共掺杂的SrF2纳米晶,并对其上转换发光性能进行了研究.X-射线衍射结果表明所制备的产物为纯的SrF2.随着溶剂热温度的升高,该纳米晶衍射峰的强度逐渐增强,且与SrF2的标准衍射峰相比,所有衍射峰均向高角度偏移.TEM的结果表明,溶剂热处理后,SrF2颗粒的分散性得到明显改善,且晶粒大小随着溶剂热温度的升高而增大.在980nm激光泵浦下Er3+和Yb3+共掺杂SrF2纳米晶仅能观察到弱的上转换发光,而在500℃和600℃热处理2h后,其上转换发光强度明显增强.上转换发光强度与泵浦功率的关系表明绿光和红光均为双光子吸收过程.     

Er~(3+)离子掺杂浓度对碲酸盐玻璃光学跃迁及上转换发光性质的影响

采用高温熔融淬火法制备了Er3+掺杂碲酸盐玻璃。测量了不同Er3+浓度掺杂的碲酸盐玻璃的吸收光谱,应用Judd-Ofelt理论计算了J-O参数Ωλ(λ=2,4,6),讨论了Er3+离子浓度对碲酸盐玻璃性质的影响。在980 nm激发下,测量了样品的上转换荧光发射谱,在室温下观察到绿光(525 nm)和红光(655 nm)发射,其分别对应于Er3+的2H11/2→4I15/2和4F9/2→4I15/2跃迁到Er3+/Yb3+,通过分析变激光功率激发下上转换发光光谱强度的变化,得到绿光和红光发射都是双光子过程。此外,还研究了样品的浓度猝灭机制,给出了交叉弛豫的路径。     

Yb3+、Er3+和Eu3+共掺杂TiO2纳米带的制备与表征

通过离子交换和水热两步合成过程简单制备了Yb3+、Er3+和Eu3+共掺杂锐钛矿型TiO2纳米带。该3种离子共掺杂未导致TiO2结构和形貌发生变化。光学特性测试结果表明,由于稀土离子掺杂浓度低,Eu3+掺杂未改变由Yb3+和Er3+产生的上转换发射峰位,但可观察到因上转换发光激发的Eu3+荧光发射峰;Eu3+荧光光谱也未受到Yb3+和Er3+掺杂的影响。通过对掺杂样品上转换发光机理的考察证实,上转换发光过程是双光子过程,但TiO2和Eu3+掺杂对此发光过程有明显影响。     

PbO对Tm3+/Ho3+/Yb3+共掺碲酸盐玻璃三基色上转换发光的影响

用高温熔融法制备了Tm3+/Ho3+/Yb3+共掺碲酸盐玻璃,在TeO2-ZnO-La2O3玻璃组分的基础上,引入声子能量较低的PbO,研究了PbO对基质样品拉曼光谱以及Tm3+/Ho3+/Yb3+共掺样品上转换发光光谱的影响.结果表明,随着PbO含量的增加,样品的最大声子能量下降比较明显,同时样品的声子态密度也有减小趋势;在975nm波长激光二极管(LD)激励下,随着PbO含量的增加,Tm3+/Ho3+/Yb3+共掺样品上转换蓝光(480nm)、绿光(546nm)和红光(662nm)的发光强度都有明显增强,且PbO的引入对上转换蓝光发光强度的影响要大于其对绿光和红光的影响.     

Er3+/Yb3+掺杂NaGd(WO4)2粉体的制备与发光性能

采用水热法成功制备了Er~(3+)/Yb~(3+)双掺杂的NaGd(WO_4)_2纳米粉体,研究了不同络合剂、水热温度对样品形貌和结构的影响。测量了不同Er~(3+)掺杂浓度样品的可见上转换和近红外发射光谱。结果表明:在980nm LD激发下,可观测到样品强烈的绿色上转换发光,对应Er~(3+)的~2H_(11/2)→~4I_(15/2)(530nm)和~4S_(3/2)→~4I_(15/2)(552nm)跃迁,以及较弱的红色上转换和近红外发光,分别对应Er~(3+)的~4F_(9/2)→4I15/2(656nm)和~4I_(13/2)→~4I_(15/2)(1 532nm)跃迁。且随着Er~(3+)掺杂浓度的增加,样品的上转换红绿光和1.54μm附近的近红外光均呈现出先增大后减小的趋势。样品的激发和发射光谱显示,在378nm处的激发峰最强,对应Er~(3+)的~4I_(15/2)→~4 G_(11/2)能级跃迁,最强发射峰位于552nm。根据泵浦功率与发光强度的关系可以得出,红光和绿光的发射主要为双光子吸收过程,但红光还包含了一定的单光子吸收成分。     

P2O3-B2O3-Al2O3-SrO-BaO玻璃中Yb3+非辐射能量转移下Er3+离子的增强发射

本文研究了共掺Er3 +/Yb3 +P2 O3 -B2 O3 -Al2 O3 -SrO -BaO玻璃的能量转移过程。实验中制备了高掺杂Yb3 +离子的双掺Er3 +/Yb3 +的磷酸盐玻璃样品。在Er3 +/Yb3 +掺杂比率 >1 :1 8(mol% )时 ,观测到了基于Yb3 +离子至Er3 +离子能量转移下Er3 +( 4 I13 / 2 →4I15 / 2 )的增强发射和Yb3 +( 2 F7/ 2 →2 F5 / 2 )发射的减弱 ,当Yb3 +离子掺杂浓度超过 2 .1× 1 0 2 1ions/cm3 时 (Er3 +/Yb3 +≤ 1 :1 8,mol% ) ,由于Yb3 +离子的自淬灭效应 ,Er3 +离子的发射强度降低。实验中得到了Yb3 +离子的最佳掺杂浓度为1 .74× 1 0 2 1ions/cm3     

Ultraviolet upconversion fluorescence of Er3+ in Yb3+/Er3+-codoped Gd2O3 nanotubes

Under 980 nm excitation, room-temperature ultraviolet (UV) upconversion (UC) emissions of Er3+ from the 4G(9/2), 2K(13/2), and 2P(3/2) states were observed in Gd2O3:Yb3+/Er3+ nanotubes, which were synthesized via a simple wet-chemical route at low temperature and ambient pressure followed by a subsequent heat treatment at 800 degrees C. The experimental results exhibited that these UV emissions came from four-photon UC processes. In the Gd2O3:Yb3+/Er3+ nanocrystals, the energy transfers (ETs) from Yb3+ to Er3+ played important roles in populating the high-energy states of Er3+ ions. This material provides a possible candidate for building UV compact solid-state lasers or fiber lasers.     

Adiabatic demagnetization of Er3+ or Nd3+ substituted YAG

The paramagnetic salts, eg alums, usually employed in adiabatic demagnetization experiments are inconvenient because of their tendency to dehydration, etc. The refractive oxides with magnetic impurities seem to be more favourable. The authors describe the results obtained with Er³⁺ and Nd³⁺ substituted yttrium aluminium garnets (YAG). Final temperatures reached after adiabatic demagnetization are comparable to those obtained with cerium magnesium nitrate. The paper illustrates the possible use of Er³⁺ and Nd³⁺ substitued in YAG for creating a very simple device for obtaining low temperatures in the mK region by adiabatic demagnetization.     

Infrared Luminescence of Y2O2S:Er3+ and Y2O3:Er3+

The diffuse reflectance and luminescence spectra of Y₂O₂S:Er³⁺ and Y₂O₃:Er³⁺ are studied under selective and polarized laser excitation. The results indicate that the Er³⁺ luminescence bands of yttrium oxysulfide in the 1.54-m region are one order of magnitude stronger and broader than those of yttria. Y₂O₂S:Er³⁺ is shown to contain two types of Er-related emission centers differing in the anion environment of the Er³⁺ ion.     

Luminescence centers in CaS:Er3+

The diffuse reflectance, photoexcitation, and luminescence spectra and luminescence decay time of CaS:Er³⁺ have been measured at 77 and 300 K and different activator contents. The absorption and luminescence bands due to Er³⁺ centers and native defects have been revealed, and the radiative electronic transitions between excited and ground Er³⁺ states have been identified. The characteristic decay times of the Er^{3+ 2} H _11/2 and ⁴ F _9/2 states in CaS have been determined, and radiative energy transfer from excited states of native defects to erbium ions in CaS:Er³⁺ has been revealed.     

NaYF4:Er3+和NaYF4:Yb3+/Er3+上转换荧光纳米晶的制备与表征

以EDTA为螯合剂,采用络合共沉淀法合成了NaYF4:Er3+和NaYF4:Yb3+/Er3+纳米晶.分别采用XRD、SEM、荧光分光光度计对合成的样品进行了结构、形貌和上转换荧光分析.XRD结果表明,制备的NaYF4:Er3+和NaYF4:Yb3+/Er3+均为纯立方相;SEM结果显示,制备的NaYF4:Er3+和NaYF4: Yb3+/Er3+晶粒粒径都在100nm左右,与NaYF4:Er3+相比,NaYF4:Yb3+/Er3+晶粒尺寸分布更均匀,分散性更好,符合作为荧光标记材料的要求;上转换荧光分析表明,在980nm激光器激发下,NaYF4:Yb3+/Er3+的发光强度比NaYF4:Er3+提高了1个数量级.     

Visible luminescence properties of Er3+–Pr3+ codoped fluorotellurite glasses

Er³⁺ and Pr³⁺ codoped fluorotellurite glasses has been synthesized. The PL spectrum revealed that the intensity of Er³⁺ characteristic emission was enhanced as Pr³⁺ concentration increased. Due to small mismatch between the energy level of Er³⁺: ⁴F_7/2 and Pr³⁺: ³P₀ resonant energy was possibly transferred between them. While Pr³⁺ concentration kept increasing, both Pr³⁺ and Er³⁺ concentration quenching occurred. These glasses with the controllable CIE coordinates might be a potential candidate for the widely application such as solid state multicolor display.     

Luminescent Properties of Y2O3:Er3+

The diffuse reflectance and luminescence spectra of Y₂O₃:Er³⁺ were studied under selective laser excitation. The results indicate that Er-doped yttria offers several sharp, strong emission bands in the IR (1.54 m) and visible ranges. Raising the doping level to 10 at. % Er increases the intensity of IR luminescence.     

Theoretical comparison of Er3+-doped crystal lasers

Abstract

The theoretical results are presented from a model that has been developed to simulate the 3 μm laser transition in Er³⁺-doped laser crystals. The rate equations for the seven lowest energy levels of Er:YAG, Er:YSGG, Er:YLF and Er:BAYF have been solved numerically for both continuous wave (cw) and pulsed (Q-switched and gain switched) laser operation with direct optical pumping into the ⁴I11/2 energy level. The dependence of slope efficiency on the Er³⁺ concentration for each laser crystal was investigated for cw operation and the relative performance of Er(15%):YLF, Er(15%):BAYF, Er(50%):YAG and Er(50%):YSGG was compared for each mode of operation. The change in the slope efficiency of Er:YLF at high Er³⁺ concentration, due to additional multi-ion processes, was calculated for a wide range of rate coefficients. It was determined that the slope efficiency could be reduced by as much as 12% by these processes and thus could explain the reduction in the slope efficiency as determined experimentally for lasers using highly doped fluoride crystals as the gain medium.     

YAG晶体中Yb~(3+)对Er~(3+)的敏化作用

根据能级跃迁速率方程得出Yb,Er:YAG中各能级布居数与Er3+离子浓度的关系.并与单掺Er:YAG中各能级布居数相比较,讨论共掺Yb3+对Er3+的波长为1.64和2.94μm两荧光的影响.结合作者关于红外光激励Yb,Er:YAG能量上转换为可见光工作,提出将Yb,Er:YAG晶体研制成以半导体激光器为激励源的可见光和1.64μm红外光的双波长全固化激光器的设想.     

Simulation of Tm 3+ -doped silica and Er 3+ -doped fluorozirconate fibre lasers

Computer simulation of the operation of diode-pumped Tm³⁺-doped silica and Er³⁺-doped fluorozirconate fibre lasers that use cladding-pumping models high-power continuous-wave output at wavelengths near 2 and 3 μm. The model has been used to examine the fibre laser performance for a variety of fibre and pump configurations. Good agreement has been found between the model calculations and published experimental measurements. The model has determined the slope effciency and relative performance of the fibre lasers when the pump wavelength was varied over the ³F₄ and ³H₄ absorption bands of Tm³⁺ and the ⁴⁺I_11/2 absorption band of Er³⁺. The calculated maximum slope effciencies were determined to be about 40, about 71 and about 31% respectively, for each absorption band pump scheme. The model was further used to analyse the fibre laser output when the Tm 3+ and Er 3+ dopant concentrations, absorption conditions and diffraction conditions are varied and the consequences on the operation of the fibre laser with these variations are discussed.