Author Affiliations
Abstract
1 Key Laboratory of Photoelectronic Materials, Ningbo University, Ningbo 315211, China
2 Ningbo Institute of Materials Technology and Engineering, the Chinese Academy of Sciences, Ningbo 315211, China
3 Department of Physics, Dalian Maritime University, Dalian 116026, China
A Ce3+ ion-doped α-NaYF4 single crystal of high quality is grown successfully by an improved flux Bridgman method under the conditions of taking the chemical raw composition of NaF:KF:YF3:CeF3 in the molar ratio of 30∶18∶48∶4, where the KF is shown to be an effective assistant flux. The x ray diffraction, absorption spectra, excitation spectra, and emission spectra of the Ce3+-doped α-NaYF4 single crystal are measured to investigate the phase and optical properties of the single crystals. The absorption spectrum of the Ce3+:α-NaYF4 shows a strong band that peaks at the wavelength of 300 nm. The emission spectrum of the Ce3+:α-NaYF4 emits an intense ultraviolet (UV) band at the wavelength of 332 nm under the excitation of 300 nm light. Two separated luminous bands of 330 and 350 nm, which correspond to the transitions 5d→F5/22 and 5<
160.0160 Materials 230.0230 Optical devices 260.1180 Crystal optics 300.0300 Spectroscopy Chinese Optics Letters
2016, 14(6): 061601
Author Affiliations
Abstract
Key Laboratory of Photo-Electronic Material, Ningbo University, Ningbo 315211, China
Glass ceramics Ba2LaF7:xDy3+ are obtained through the conventional melt-quenching technique, and their luminescent properties are investigated. Under 350 nm excitation, the emission spectra consists of a strong blue-yellow band as well as a weak red emission centered at 660 nm, which are attributed to the F9/24→H15/26, F9/24→H13/26 and F9/24→H11/26 transitions of the Dy3+ ion, respectively. The corresponding Commission Internationale de L’Eclairage (CIE) chromaticity coordinate for a sample of 2 mol.% Dy2O3 after being heat-treated at 690°C is (0.313, 0.328). It is concluded that the formed materials may have the possibility of applications for white light-emitting diodes (LEDs).
160.2540 Fluorescent and luminescent materials 160.4760 Optical properties 160.5690 Rare-earth-doped materials Chinese Optics Letters
2015, 13(9): 091601
Author Affiliations
Abstract
Mid-infrared (MIR) emissions of 2.4 and 3.5 m from Tm3+:LiYF4 single crystals attributed to 3H4->3H5 and 3H5->3F4 transitions as well as MIR emissions of 4.2, 4.3, and 4.5 \mu m from Nd3+: LiYF4 lasers attributed to 4I15/2->4I13/2,4I13/2->4I11/2, and 4I11/2->4I9/2 transitions, respectively, are observed. LiYF4 single crystals possess high transmittance of over 85% in the 2.5-6 \mu m range. The large emission crosssections of Tm-doped crystals at 2.4 \mu m (1.9\times 10-20 cm2) and Nd-doped crystals at 4.2 \mu m (0.84\times 10-20cm2) as well as the high rare-earth doping concentrations, excellent optical transmission, and chemicalphysical properties of the resultant samples indicate that Nd3+ and Tm3+ singly doped crystals may be promising materials for application in MIR lasers.
160.3380 Laser materials 160.4760 Optical properties 160.5690 Rare-earth-doped materials 140.3380 Laser materials Chinese Optics Letters
2014, 12(2): 021601
宁波大学光电子功能材料实验室, 浙江 宁波 315211
用高温熔融法制备了Ce3+/Tb3+掺杂的高钆镥氟氧化物闪烁玻璃样品，测试分析了其密度、透射光谱、激发与发射光谱、X射线激发发射光谱及衰减曲线等。制备的闪烁玻璃具有高的闪烁光输出，密度大于5.8 g/cm3，闪烁玻璃中Ce3+离子的引入有利于促进Tb3+离子发光。用Inokuti-Hirayama(I-H)理论模型分析了铈/铽掺杂高钆镥闪烁玻璃的能量传递机理，分析结果表明Ce3+→Tb3+的能量传递形式是无辐射共振能量传递。通过拟合数据和理论公式计算出了两者之间能量传递的速率和效率，其能量传递速率PSA和Tb3+离子浓度的平方成正比关系，而能量传递效率η随Tb3+离子浓度增加而升高。
材料 闪烁玻璃 光谱分析 I-H理论模型 能量传递
宁波大学光电子功能材料实验室, 浙江 宁波 315211
实验中采用高温熔融法制备了一系列高钆镥硼硅酸盐新型玻璃体系样品，研究了这种新型玻璃体系的玻璃形成区，测量了样品的玻璃稳定性和密度。结果表明，玻璃体系的玻璃形成区较广，玻璃稳定性良好（析晶温度与转变温度的差为262 ℃），且玻璃样品的密度达到5 g/cm3。以此种玻璃体系作为基质掺入Ce3+离子，测量其透过光谱、激发光谱、发射光谱、X射线激发发射光谱以及Gd3+离子的衰减时间。结果表明，玻璃的透过性能适合Ce3+离子的掺杂，并且Gd2O3和Lu2O3对闪烁体发光都具有积极的影响，同时研究了Gd3+离子和Ce3+离子的能量传递机理及最佳能量传递掺杂摩尔比。从玻璃的物理性能和光谱性能考虑，这种闪烁玻璃系统具有广泛应用于高能物理材料中的一定潜力。
材料 闪烁玻璃 光谱分析 钆镥硼硅酸盐 高密度
宁波大学 光电子功能材料研究所, 浙江 宁波 315211
用高温熔融法制备了Eu3+掺杂的碲酸盐闪烁玻璃。测试了Eu3+不同掺杂浓度玻璃样品的密度、差热特性、吸收、发射、激发光谱及X射线激发下的闪烁光谱。研究了不同Eu3+掺杂浓度对玻璃样品的密度、光谱性能的影响规律及掺杂离子的浓度猝灭效应。研究结果表明: Eu3+掺杂碲酸盐具有较大的密度和较强的闪烁发光, 随着Eu3+浓度增加, 由于Eu3+间的间距减小, 共振能量转移几率增大, 致使发光强度增强; 但当掺杂到7mol%的高浓度时, 会发生浓度猝灭效应。
Eu3+离子 碲酸盐玻璃 闪烁性能 Eu3+ ion tellurite glasses scintillating property
Author Affiliations
Abstract
A high-quality Cr3+:CdWO4 single crystal at a size of approximately \Phi 25 \times 80 mm is grown using the Bridgman method with CdO, WO3, and Cr2O3 as raw materials and their molar ratio of 100:100:0.5. The temperature gradient of solid-liquid interface at growth is approximately 50 oC/cm and the growth rate is 0.05 mm/h. The X-ray diffraction (XRD), absorption, excitation, and emission spectra of different parts of the as-grown and O2-annealed crystals are investigated. Two strong broad optical absorption bands of about 472 and 708 nm are observed, and they are associated with the transitions 4A2->4T1 and 4A2->4T2. The weak 4T2->2E transition (the R-line) at 632 nm is also observed. The crystal-field parameter Dq and the Racah parameters B and C are estimated to be 1 412.4, 776.8, and 3 427.6 cm-1, respectively, according to the absorption spectra and crystal-splitting theory. A broadband fluorescence at about 1 000 nm due to 4T2->4A2 transition is produced by exciting the samples at 675 nm. After being annealed in an O2 atmosphere, the crystals become more transparent, while the effective light absorption of Cr3+ ions is evidently enhanced and the emission intensity is also strengthened due to the reduction of oxygen vacancies in the CdWO4 crystal after annealing.
230.5298 Photonic crystals 260.1180 Crystal optics Chinese Optics Letters
2012, 10(4): 042301
1 宁波大学光电子功能材料重点实验室, 浙江 宁波 315211
2 华南理工大学光通信材料研究所特种功能材料教育部重点实验室, 广东 广州 510640
用高温熔融法制备了不同Tm3+摩尔分数掺杂的摩尔分数比为0.3(SiO2)0.1(Al2O3)0.1(AlF3)0.5(PbF2)x(Tm2O3)(摩尔分数x=0.5%,1.0%,2.0%,3.0%)玻璃。从吸收光谱特性出发,应用Judd-Ofelt理论,计算得到了Tm3+的J-O强度参量(Ω2,Ω4,Ω6)及Tm3+各激发能级的自发辐射跃迁概率、荧光分支比以及辐射寿命等光谱参量。在808 nm波长的激光二极管激发下,研究了不同Tm3+掺杂摩尔分数下玻璃在约1.47 μm与约1.8 μm处的荧光特性,在掺杂摩尔分数约达到2.0%时,在1.8 μm处的荧光强度达最大,然后随着掺杂摩尔分数的增大,其荧光强度反而降低。作者从Tm3+的交叉弛豫与摩尔分数猝灭效应解释了这一荧光强度变化的规律,同时,根据McCumber理论计算了Tm3+跃迁3H6→3F4的吸收截面和跃迁3F4→3H6的受激发射截面。
光学材料 掺铥氟氧化物玻璃 光谱性质 交叉弛豫效应
宁波大学光电子功能材料重点实验室, 浙江 宁波 315211
以K2O为助熔剂,在较大的固液界面温度梯度条件下,应用坩埚下降法技术生长了初始Ni2+掺杂摩尔分数为0.5％的近化学计量比铌酸锂晶体。测定了晶体的吸收光谱,观测到由Ni2+离子在八面体中3A2g(F)→3T1g(P)、3A2g(F)→3T1g(F)、3A2g(F)→3T2g(F)能级的正常自旋允许跃迁所产生的381 nm,733 nm,1280 nm吸收峰和3A2g(F)→1T2g(D)和3A2g(F)→1E(D)能级的自旋禁戒跃迁产生的430 nm与840 nm吸收峰。从晶体紫外吸收边的位置初步估算其摩尔分数比x(Li+)/x(Nb5+)为0.981。根据晶体分裂场理论和吸收光谱,计算了Ni2+在该铌酸锂晶体中的晶格场分裂参量Dq=781 cm-1、Racah参量B=1096 cm-1与C=4353 cm-1。研究了在不同激发波长下晶体在可见光波段的荧光特征,观察到500～630 nm的绿色与800～850 nm的红色荧光发射带,它们归结为1T2g(D)→3A2g(F)与1T2g(D)→3T2g(F)的能级跃迁所致。
光学材料 镍掺杂近化学计量比铌酸锂晶体 助熔剂坩埚下降法 Ni2+离子 光谱
宁波大学光电子功能材料重点实验室，宁波 315211
测量了Eu3+(lmol%)掺杂(60－χ)Bi2O3－χ TeO2－30B2O3－10ZnO(χ=5，10，20，30，摩尔百分比)玻璃的吸收光谱、发射光谱、激发光谱以及声子边带谱．根据稀土离子Eu3+光学跃起矩阵元的特点，从发射光谱获得了Eu3+光学跃起的J－O参数Ω2与Ω4．结果显示，强度参量Ω2随着Bi2O3量的增加与TeO2量的减少而减小，表明材料的对称性提高，Eu－O键强减弱，共价性减弱．随着Bi2O3量的增加，电一声子偶合减弱，材料的热稳定性大幅度提高．
光谱 Eu3+掺杂铋基玻璃 强度参量 声子边带谱 热稳定性 Optical spectra Eu3+-doped Bi-based glass Intensity parameters Phonon-side bands Thermal stability
