高热稳定CaGdAlO_(4)∶Er^(3+)/Yb^(3+)荧光粉的上转换发光及其温度传感性能

获得具有良好热稳定性和发光性能的非接触式光学温度传感材料是目前的研究热点之一,本工作通过高温固相法制备了Er^(3+)/Yb^(3+)共掺CaGdAlO_(4)∶Er_(x),Yb_(0.10)(x=0.006、0.008、0.010、0.012、0.014)荧光粉,尺寸大小分布在0.6~4.2μm。在980 nm激光激发下,该荧光粉在500~700 nm发射谱由两个发射带组成,528和550 nm处两个较强的绿光发射带,归属于Er^(3+)的^(2)H_(11/2)→^(4)I_(15/2)、^(4)S_(3/2)→^(4)I_(15/2)能级跃迁,663 nm处较弱的红光发射带,归属于Er^(3+)的^(4)F_(9/2)→^(4)I_(15/2)能级跃迁。上转换发光强度最大组分为CaGdAlO_(4)∶Er_(0.010),Yb_(0.10)。300~573 K变温发射谱表明,基于荧光强度比FIR_(528/550)参数,温度传感绝对灵敏度S_(A)从44.4×10^(-4) K^(-1)(@300 K)先增大到52.0×10^(-4) K^(-1)(@445 K)随后减小到49.0×10^(-4) K^(-1)(@573 K)。相对灵敏度S_(R)则从0.95×10^(-2) K^(-1)(@300 K)单调减小到0.27×10^(-2) K^(-1)(@573 K)。冷热循环实验表明该材料的热重复性优于98%。结果表明,CaGdAlO_(4)∶Er_(0.010),Yb_(0.10)荧光粉在光学温度传感领域具有潜在的应用前景。

Er^(3+)掺杂锗酸盐激光玻璃猝灭浓度的计算与预测

稀土掺杂激光玻璃光纤是光纤激光器的核心增益介质,其中稀土离子掺杂浓度是决定激光玻璃增益特性的重要参数,如何快速有效地确定最佳掺杂浓度是稀土掺杂激光玻璃光纤的关键科学问题之一。本文以Er^(3+)掺杂锗酸盐激光玻璃为例,利用Er^(3+):^(4)I_(13/2)→^(4)I_(15/2)跃迁的自发辐射跃迁寿命和实测寿命,预测了锗酸盐激光玻璃的猝灭浓度。研究表明,在该玻璃体系中,理论预测与实际值的最大绝对误差小于0.4%。对比唯象模型和有限扩散模型分别拟合多个样品发光强度和实测寿命确定猝灭浓度的方法,本文提出的方法仅需通过少量样品的测试参数即可确定激光玻璃猝灭浓度,简单快捷且计算误差小,对高增益激光玻璃与光纤研究具有指导意义。

Preparation and Luminescence of Er^(3+) Doped Oxyfluoride Glass Ceramics Containing LaF_3 Nanocrystals

Er^3＋ doped transparent oxyfluoride glass ceramics version and near infrared luminescence behavior of Er^3＋ in containing LaF3 nanocrystals were prepared and the up-conglasses heat-treating time and temperature, the size （varied from 0 to 19 and glass ceramics were investigated. With increasing nm） and crystallinity （varied from 0 to 47%） of LaF3 nanocrystals in the glass ceramics are increased. The up-conversion luminescence intensity of Er^3＋ ions in the glass ceramics is much stronger than that in the glasses The near infrared emission of Er^3＋ ions in and increased significantly with increasing heat-treating time and temperature the glass ceramics is found to be similar to that in the glasses.

Preparation and Optical Properties of Er^(3+)-Doped Gadolinium Borosilicate Glasses

Er^(3+)-doped Gd_2O_3 -SiO_2 -B_2O_3 -Na_2O glasses were prepared, and formation range of glass of Gd_2O_3 -SiO_2 -B_2O_3 system was experimentally obtained. It is found that the glass phase can be formed only when the content of SiO_2 is 0～50%(molar fraction), Gd_2O_3 is 0～30%(molar fraction) and B_2O_3 is above 20%(molar fraction) in this glass system. The glass can also be obtained but becomes translucent at the contents of 60%(molar fraction) SiO_2 and 30% Gd_2O_3 , or at the contents of 60%(molar fraction) SiO_2 and 30%(molar fraction) B_2O_3. There is no glass phase formed in other glass components. Glass forming ability for Gd_2O_3 content of 10%, was characterized by the value of β, the parameter of crystallization tendency, which is 0.32～1.76, obtained from the differential thermal analysis. The absorption and emission cross section, the J-O parameters Ωt_((2,4,6)) and radiative transition probabilities were calculated by using the theory of McCumber and Judd-Ofelt. The emission properties at 1.5 μm of the samples are discussed with the product of full width at half maximum and stimulated emission cross section. It can be seen that the value of the FWHM×σ_e^(peak) product in the prepared glass is more than those of germanate, silicate and phosphate glasses. Furthermore, the maximum value of the product among these glasses reported in this work is close to that of oxyfluoride silicate glass. Therefore, the Er^(3+)-doped gadolinium borosilicate glass in this paper is a candidate for broadband erbium doped fiber amplifiers.

Preparation and Optical Properties of Er^3+:Na2O-Al2O3-SiO2 Transparent Glass-Ceramics

Na2O-Al2O3-SiO2 glass-ceramics doped with Er^3＋ ions were synthesized by the conventional melt quenching technique at a low melting temperature.The samples were characterized by differential scanning calorimetry（DSC）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,UV-vis-NIR scanning spectrophotometry,and fluorescence spectrometry.The results show that the main crystalline phase of glass-ceramics is nepheline.The best heat-treatment process is at 520 ℃ for 2 h.Because the up-conversion luminescence and near infrared luminescence properties of glass doped with Eu^3＋ are studied in detail.

Theoretical Analyses of 4f^11→4f^105d Excitation Spectra of Er^3＋ Doped in LiYF4

Spectral terms and J-spectral multiplet of low-spin 4f105d configuration of Er3+ were obtained with the method of ligand field theory. According to the selection rules for dipole transitions, the excitation spectra of Er3+ doped in LiYF4 in vacuum ultraviolet region (120～160 nm) of the spectrum were theoretically interpreted by applying the crystal field model, and the six bands were assigned to the spin-allowed transitions from the ground state (4I15/2) to J-spectral multiplet of low-spin 4f105d configuration of Er3+ion.

Upconversion properties of Er^3＋/Yb^3＋ co-doped TeO2-Nb2O5-Li2O glasses

The Er^3＋/Yb^3＋ co-doped TeO2-Nb2O5-Li2O glass is prepared by conventional melting method, and its upconversion spectra are measured. The intense green upconversion luminescence upon excitation with a 976 nm laser diode is observed with the naked eyes. The dependence of luminescence intensity on the ratio of Yb^3＋/Er^3＋ is discussed in detail, and the relationship between the ratio of green luminescence intensity to red luminescence intensity and the ratio of Yb^3＋/Er^3＋ is also studied, The luminescence intensity increases with the ratio of Yb^3＋/Er^3＋ increasing. The ratio of Yb^3＋/Er^3＋ plays a more important role than the concentration of Er^3＋ in determining the upconversion luminescence intensity. The ratio of green luminescence intensity to red luminescence intensity reaches a maximum when ratio of Yb^3＋/Er^3＋ is 3. Thus the glass could be one of the potential candidates for LD pumping solid-state lasers.

Role of incoherent pumping and Er^(3+) ion concentration on subluminal and superluminal light propagation in Er^(3+)-doped YAG crystal

We study the absorption-dispersion process and group index of weak probe field in a four-level Er^3＋：YAG crystal.We find that the Er^3＋ion concentration and incoherent pumping field can influence the absorption-dispersion process and group index of weak probe field. Moreover, our results show that Er^3＋ion concentration plays a major role in lasing without inversion and absorption with inversion.

掺Er^(3+)重金属氧氟硅酸盐玻璃的光谱性质与Judd-Ofelt理论分析

制备了掺Er3+重金属氧氟硅酸盐玻璃,研究了玻璃的吸收光谱和荧光光谱性质,应用Judd Ofelt理论计算了强度参数Ωt(t=2,4,6)、Er3+离子的振子强度、自发辐射跃迁几率、荧光分支比和辐射寿命等光谱参数。应用McCumber理论,计算了能级4I13 2→4I15 2跃迁的受激发射截面。结果表明:掺Er3+重金属氧氟硅酸盐玻璃具有较宽的荧光半高宽和较大的受激发射截面。对Er3+离子在不同玻璃基质中带宽特性的比较发现,掺Er3+重金属氧氟硅酸盐玻璃的带宽特性与碲酸盐和铋酸盐玻璃相当,大于磷酸盐、锗酸盐和硅酸盐玻璃。

含纳米晶颗粒的Yb^(3+)/Er^(3+)共掺透明碲酸盐玻璃陶瓷的光谱性质研究

在组成为15Li2O-15Nb2O5-70TeO2-0.1Er2O3-0.4Yb2O3(%,摩尔分数)的碲酸盐玻璃基础上,采用两步热处理法制备了透明的含纳米晶颗粒碲酸盐玻璃陶瓷。通过X射线衍射(XRD)测试表明,玻璃陶瓷中的晶体颗粒组成为Yb6Te5O19.2或Er6Te5O19.2,晶粒尺寸约为55 nm。根据Judd-Ofelt理论计算了Er3+离子在基质玻璃和玻璃陶瓷中的光谱参数Ωt(t=2,4,6)以及Er3+∶4I15/2→4I13/2跃迁自发辐射几率,根据Mc-Cumber理论计算了Er3+∶4I13/2→4I15/2跃迁的发射截面。测试了基质玻璃和玻璃陶瓷的拉曼光谱,对比研究了铒离子在基质玻璃和玻璃陶瓷中1.5μm处荧光和上转换光谱特性。

温度对YLiF∶Er^(3+)上转换发光的影响

研究了用水热法合成的YLiF4∶Er3+的上转换发光特性。用980nm的光激发样品时,得到了很强的绿光554nm和红光666nm。对应Er3+离子不同能级的上转换发射为双峰发射,表明基质中Er3+离子处于两种不同的格点上。改变测试温度时,样品的上转换发光强度随着温度的升高而下降。室温下,绿光的上转换机制是双光子和三光子混合过程,红光为双光子过程。

Er^(3+)掺杂的氧化钇纳米材料上转换发光性质的研究

利用燃烧法制备了稀土Er3+离子掺杂的氧化钇纳米晶材料。用JEM3010测量这种材料的结构与样品颗粒的分布,结果表明:晶粒尺寸约为30nm。用日立F-2500荧光光谱仪与978nm LD测量了该材料的上转换发光,得到该样品主要发绿色上转换发光,红色上转换发光非常弱。我们认为,这种现象与基质材料的低的声子能量与低的掺杂浓度有关。

Ce^(3+)对Er^(3+)的上转换荧光淬灭

提要:本文研究了Ce3+离子对Er3+离子的上转换荧光淬灭规律,随着Ce3+离子浓度增加,Er3+离子各波段的上转换荧光强度迅速下降,并且发现红色荧光带的淬灭要快于绿色荧光带。具体分析了Er3+离子的上转换荧光的产生机制,通过分析Ce3+对Er3+离子淬灭机理,进一步讨论了Er3+离子的上转换机制。

Yb^3＋／Er^3＋双掺氟氧硅酸盐玻璃

系用熔融技术制备了Yb^3＋／Er^3＋双掺氟氧化物微晶玻璃，通过实验确定了掺稀土离子微晶玻璃的配比、熔化温度和退火温度。采用ACTO-2758光谱仪测得样品的拉曼光谱，并讨论基质成分的声子能对发光效率的影响。采用日本产的Hitachi F-4500荧光光度计，激发波长为980nm激光器测定了样品的发射光谱。通过对光谱的分析，建立了上转换发光机制。测量了发光强度与抽运功率的关系，通过非线性拟舍得出的斜率，确定了样品的528nm，542nm和655nm发射均为双光子过程。

Er^(3+)掺杂含Ba_2LaF_7纳米晶氧氟硼硅酸盐玻璃陶瓷发光性能的研究(英文)

制备了含有Ba2LaF7纳米晶的Er3+掺杂氧氟硼硅盐玻璃陶瓷,并对其光谱特性进行了研究.根据X射线粉末衍射结果可确认制备出Ba2LaF7纳米晶.根据吸收曲线计算了相应的Judd-Ofelt参数,Ω2随着热处理温度的升高而减小,证明Er3+离子进入到Ba2LaF7纳米晶中.由于Ba2LaF7纳米晶的低声子能量,在玻璃陶瓷中观察到强烈的红光和绿光上转换发光,其上转换发光机理可以归为双光子过程.

掺Er^(3+)重金属氧氟锗酸盐玻璃光谱性质研究

研究了重金属氧氟锗酸盐玻璃中Er3+离子的吸收光谱、有效吸收和发射线宽、荧光光谱、荧光半高宽、荧光寿命、带宽特性和增益性能.应用Judd-Ofelt理论计算了Er3+离子的强度参数Ωt(t=2,4,6),应用McCumber计算了能级4I13/2→4I15/2跃迁的吸收和受激发射截面.结果显示,随PbF2含量增加,Er3+离子的强度参数Ω6,吸收线宽、发射线宽、荧光半高宽、荧光寿命、带宽特性和增益性能都增加.表明掺Er3+重金属氧氟锗酸盐玻璃可作为宽带光纤放大器潜在的基质材料.

氟氧化物中Er^(3+)的上转换发光

研究了Er3 + 离子氟氧化物的上转换发光。在 980nm光的激发下 ,测量了Er3 + 离子浓度 (分别为 1mol%、2mol %、3mol% )不同时材料的上转换发光光谱。在可见光范围内 ,观察到了强红光和绿光 ,并且在短波段也观察到了光的发射 ,波峰分别位于 661、5 45、45 6、40 9和 3 80nm处。还测量了各样品的上转换发光强度随激发强度的变化情况 ,由LogIvis-LogIin曲线可知 ,红光为双光子过程和三光子过程 ,绿光为三光子过程。并初步研究了此材料的上转换过程和上转换通道。

铒离子浓度对掺Er^(3+)碲酸盐玻璃的Judd-Ofelt理论参数的影响

制备了四种不同铒离子掺杂浓度的碲酸盐玻璃,通过测定吸收光谱计算了吸收谱线的振子强度,根据Judd-Ofelt理论计算了不同浓度下Er3+离子发光光谱的强度参数Ωi(i=2,4,6),计算了自发辐射电偶和磁偶跃迁概率、辐射寿命、荧光分支比等参数,讨论了Er3+离子浓度变化对以上这些参数的影响。测试了Er3+4I13/2→4I15/2跃迁对应的荧光光谱和Er3+4I13/2能级荧光寿命。最后应用McCumber理论计算了玻璃中Er3+4I13/2→4I15/2跃迁对应的受激发射截面大小。结果表明振子强度基本上随Er3+离子浓度的增大而增强;随着Er3+离子浓度的增加,自发辐射跃迁概率A基本呈现出递增的趋势,但荧光分支比β却只有很小的变化;Er3+4I13/2→4I15/2的发射截面随Er3+离子浓度的增大而改变很小,有效线宽都在50nm左右。

GdCOB:Er^(3+),Yb^(3+)晶体的光谱分析

生长了新型激光晶体 Gd Ca4 O( BO3) 3:Er3+ ,Yb3+ (简称 Gd COB:Er3+ ,Yb3+ ) ,并测量了其室温透过谱、荧光谱及红外吸收谱。在 974nm的二极管泵浦下 ,观察到微弱的绿光发射 ,在 1 536nm左右的荧光发射较强。讨论了 Gd COB:Er3+ ,Yb3+ 晶体中 Yb3+ → Er3+ 的能量传递 ,解释了绿光发射 ,提出 Yb3+ 合作向 Er3+ 进行能量传递的机制。

Er^(3+)离子掺杂的碲酸盐玻璃光谱性质分析

用976 nm光激发测量了室温下掺Er3+碲酸盐玻璃的上转换发光,讨论了上转换发光机制.同时测量了掺Er3+离子碲酸盐玻璃的吸收光谱和荧光光谱,发现掺Er3+离子碲酸盐玻璃的荧光半高宽可达80 nm,应用McCumber理论计算了1 531 nm处的受激发射截面可达0.75×10-20cm2.对Er3+离子在不同基质玻璃中光谱特性的比较,发现了Er3+离子在碲酸盐玻璃中具有相对较高的受激发射截面和宽的荧光半高宽.