The Study on the Interaction between Tm3+ and Tb3+ Rare Earth Ions in YVO4 Crystal

In this paper the measurement result of transmission spectrum of Tb,Tm∶YVO4 is presented. The intensity Ωt, the probabilities of radiating transition, non-radiating transition, the cross-relaxation and the lifetimes of Tm3+ ions at 3H4 and 3F4 levels are calculated. The results show that when the concentration of Tm3+ ions >1.2 at.-%, the fluorescent lifetime of upper level 3H4 is shorter than that of lower level 3F4 due to the interaction between Tm3+ and Tb3+ ions, thus the lasing self-termination at ～1.5 μm can be eliminated.     

双掺(Tm3+,Tb3+)LiYF4激光器1.5 μm波长激光阈值分析

由速率方程推出了双掺（Tm^3 ,Tb^3 ）离子准四能级系统的激光阈值解析式，讨论了Tm^3 和Tb^3 离子之间的相互作用。分析了1.5μm波长附近的激光阈值和Tm^3 、Tb^3 离子的掺杂原子数分数及晶体长度的关系。结果表明，对于对应Tm^3 离子^3H4→^3F4跃迁的约1.5μm波长的激光，激活离子Tm^3 的掺杂原子数分数过大时，交叉弛豫作用将使系统阈值迅速增加。Tb^3 离子的加入，一方面能抽空激光下能级，起到降低阈值的作用；另一方面亦减少了激光上能级的寿命，使阈值升高。故Tb^3 离子有最佳掺杂原子数分数。对于Tm原子数分数为y=0.01的Tm:LiYF4晶体，Tb^3 离子的最佳掺杂原子数分数为0.002左右，同时表明，激光阈值与晶体长度有关。最佳晶体长度与Tm^3 、Tb^3 离子的掺杂原子数分数以及晶体的衍射损耗和吸收损耗有关。     

LaOBr中Ce—Tb、Tm—Er间能量传递的光声光谱和光致发光研究

本文首次报导了发光材料中两个不同稀土离子间能量传递的光声光谱研究。测量了LaOBr:Tb,Ce和LaOBr:Er,Tm体系的光声光谱,结合它们的光致发光特性,讨论了Ce³⁺对Tb³⁺的敏化、Tm³⁺对Er³⁺的猝灭。基质中掺入两种不同稀土离子后光声光谱的变化进一步证实了它们间的能量传递都伴随着多声子过程。分析LaOBr:Er,Tm的光声光谱,对Er³⁺r的红光猝灭的机制提出了新的解释。     

TbxTmyY1-x-yP5O14晶体中Tb3+和Tm3+间的能量转移

本文提出了Tb3+和Tm3+的交叉弛豫机理,计算了交叉弛豫几率,研究了Tm3+对Tb3+离子发光性质的影响,结果指出Tm3+对Tb3+离子的5D3能级的荧光有很强的猝灭作用,对5D4能级的荧光有增强作用,并且给出Tb的荧光强度和Tb3+,Tm3+离子浓度之间的依赖关系。     

Critical separation for efficient Tm3+ -Tm3+ energy transfer evidenced in nanostructured Tm3+: Al2O3 thin films

Nanostructured amorphous Al oxide (a-Al2O3) thin films doped with Tm3+ were synthesized by alternate pulsed laser deposition. The Tm3+ ions have been deposited in layers with in-depth separation ranging from 0.75 to 6 nm. The films show two broad emission bands originated from the Tm3+ 3H4-->3F4 and 3F4-->3H6 transitions. Their intensity increases at a similar rate and the lifetimes are not modified as the layer separation decreases down to 1.5 nm, suggesting that there is no concentration quenching. At the critical value of 1.5 nm the onset of Tm3+ -Tm3+ energy transfer is evidenced by a sharp decrease of the emission intensity and lifetime. Below this critical value, the rate at which the intensity increases for the 3F4-->3H6 transition is much higher than that for the 3H4-->3F4 transition, evidencing quenching of the 3H4-->3F4 transition through a cross-relaxation mechanism. The control of the Tm3+ ions in the nanometer scale allows evidencing the onset of energy transfer processes among ions and offers a route to optimize compact photonic gain integrated devices.     

Tb，Tm：YVO4晶体的激光性能分析

Tm：YVO4和Tb，Tm：YVO4晶体中激活离子之间或激活离子与敏化离子间的交叉弛豫、与无辐射跃迁及激光上能级的辐射跃迁的几率是相近的，对这种双掺离子晶体的激光阈值理论估算式中必须同时考虑离子间交叉弛豫。从激活离子能级跃迁速率方程和激光、抽运光传输方程推导出端面抽运的包含交叉弛豫几率等光学参量的激光阈值的理论估算式。用这些方程讨论了Tm：YVO4和Tb，Tm：YVO4的1．5μm和1．9μm波长的激光性能，并论述了Tb3 离子的作用。结果表明。Tb3 离子的的掺入，增加1．5μm波段激光的强度，降低阈值能量，但对1.9μm波长激光有负面作用。     

Tb3+离子在碱土金属正硅酸盐中的发光

Tb3+离子激活的Me2SiO4(Me=Ca、Sr、Ba)发光材料是用分析纯试剂合成并加以提纯的BaCO3、SrCO3、CaCO3、H2SiO3、Li2CO3和Tb2(C2O4)3为原料,通过固态反应的合成方法而制成的。由X-光衔射谱,确定了样品的结构。通过荧光测量,探讨了Tb3+离子在碱土金属正硅酸盐中的发光行为。     

ZnS:TbF3,ErF3,HoF3ACTFEL的亮度与跃迁几率的关系

测量了低浓度下ZnS:TbF3,ErF3和ZnS:TbF3,HoF3交流电致发光薄膜(ACTFEL)中的Tb3+,Er3+,HO3+主要发射峰的相对积分强度,并与Tb3+,Er3+,Ho3+主要发射能级的辐射跃迁几率及高浓度时的发光特性进行了比较,发现稀土氟化物掺杂的ZnS薄膜电致发光(ACTFEL)的最大亮度,不完全取决于稀土离予本身的辐射跃迁几率,而主要取决于稀土离子主要发射能级激发态的运动。本文首次给出了Tb3+离子在ZnS中的强度参数Ω2=3.2×10-19cm2,Ω4=1.6×10-19cm2,Ω6=2.6×10-19cm2,并应用这组Ωλ参数估算了Tb3+离子的交叉弛豫(cross-relaxation)几率。     

Analysis of the laser performance of Tm3+, Tb3+(Ho3+):YVO4 crystals at ～1.5μm wavelength

The absorption spectra of Tb,Tm:YVO_4 and Ho,Tm:YVO_4 are measured. The radiant and non-radiant transition probabilities from higher level to lower level, A_{i,j} and ω_{i,j}, and the cross-elaxation probability are calculated in virtue of Judd－Ofelt and Dexter theories. The fluorescence lifetime of Tm^{3+} in the Tb^{3+} (or Ho^{3+}) co-doped crystal is calculated. It indicates that the lifetime of initial level {}^3H_4 of the laser transition can be shorter than that of terminal level {}^3F_4 of the transition if the atomic percentage of Tb^{3+} (or Ho^{3+}) ions is bigger than about 1 at%: namely, by means of the co-doping Tb^{3+} (or Ho^{3+}) ions the self-termination phenomenon of laser light can be eliminated. Inserting the optic parameters to the formula deduced here on the laser threshold power P^{(4)}_{th} and the slope efficiency η^{(4)}_s of the four-energy-level system, we obtain the relationship of threshold power P^{(4)}_{th} to the concentration of Tm^{3+} ions and discuss the effect of Tb^{3+} (or Ho^{3+}) ion concentration on the laser threshold power P^{(4)}_{th} around 1.5μm wavelength. The result shows that Tb,Tm:YVO_4 crystal is a better choice to make the laser at ～1.5μm wavelength than Ho,Tm:YVO_4 crystal. We give the appropriate composition of (1－2) at% Tb, (1－2) at% Tm:YVO_4, just for reference.     

Sr3Gd(PO4)3:Tm3+的真空紫外光谱特性

研究了Sr3Gd(PO4)3 : Tm3 和GdPO4 : Tm3 样品的结构特性、光谱特性.GdPO4 : Tm3 为单斜晶系,基质掺入铥离子后结构没有明显变化.GdPO4:Tm3 在164和210 nm附近有强烈的吸收峰.位于164 nm附近的强烈的吸收峰是归因于基质的吸收引起,210 nm附近的吸收峰则归因于Gd 的8S7/2-6GJ的能级跃迁.在164 nm真空紫外光激发下,样品于453及363 nm处有较强的发射峰,发射主峰位于453nm,属于Tm3 的1D2→3H4(22,123 cm-1)跃迁的典型发射.由于阳离子质量的不同,Sr3Gd(PO4)3:Tm3 在166 nm附近的激发峰高于GdPO4: Tm3 的同位置的激发峰,其在363 nm处的发射有明显减弱,而在453 nm处的蓝色发射有显著的增强.     

高掺杂Ce3+,Tb3+在正硼酸盐中的发光特性及能量传递

本文利用纳秒技术和一般光谱学技术系统地研究了Ce3+,Tb3+离子在LnBO3(Ln=La,Gd和Y)中的发光特性和能量传递机制.发现在La1-xCexBO3中Ce3+离子的浓度在0.1mol以上才出现明显的浓度猝灭.故对敏化剂Ce3+可以高浓度掺杂.本文对高掺杂下材料的发光特性,Ce3+到Tb3+能量传递的规律和机制进行了系统研究.给出了在正硼酸盐中绿色发光材料的最佳配比.     

Tm~(3+)/Yb~(3+)共掺氟氧化物碲酸盐玻璃的上转换发光及光学温度传感

采用高温熔融淬火法成功的合成了Tm~(3+)/Yb~(3+)共掺杂的含有不同浓度Tm~(3+)的氟氧化物碲酸盐玻璃.测量了样品的吸收光谱,结果表明Yb~(3+)和Tm~(3+)成功掺入到玻璃基质中.在980nm激发下,样品在801nm(3H4→3H6)发射最强,在476nm(1G4→3H6)和651nm(1G4→3F4)发射较弱;分析了上转换发光强度与Tm~(3+)浓度依赖关系,确定了上转换发光的最佳掺杂浓度为0.1%Tm2O3;探讨Tm~(3+)的上转换发光机理和Tm~(3+)的浓度猝灭机理,结果表明在980nm激发下Tm~(3+)获得的能量主要来自于Yb~(3+)→Tm~(3+)的量传递,Tm~(3+)的浓度猝灭机理为Tm~(3+)-Tm~(3+)之间的交叉弛豫导致的无辐射能量传递,根据能量匹配的原则,给出可能的交叉弛豫通道.此外,在980nm激发以3F2,3和3H4作为热耦合能级研究分析了Tm~(3+)在氟氧化物碲酸盐玻璃中的温度传感性能,结果表明灵敏度随温度的升高而升高,说明Tm~(3+)掺杂的氟氧化物碲酸盐玻璃可以作为光纤传感材料,且在高温灵敏度更佳.     

YAG晶体中Tm^3＋离子的荧光特征分析

计算了ＹＡＧ晶体中Ｔｍ＾３＋离子辐射跃迁几率Ａｉｊ，无辐射跃迁几率Ｗｉｊ，交叉弛豫几率Ｐ，荧光寿命τｉ和荧光分支比βｉｊ等荧光特征参量，并利用这些值及跃迁速率方程讨论了＾３Ｆ４能级荧光强度与掺杂浓度的关系，得出当激发光的泵浦速率从１０＾２～１０＾６ｓ＾－１时，Ｔｍ＾３＋离子的最佳相对浓度Ｘｏｐ在４．９～６．４％之间。     

Spectroscopic Properties and Energy Transfers in Tm ~(3 ) and Yb~( 3 )/Tm ~( 3 ) Doped Fluoroaluminate Glass

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｔｈｅｔｒａｎｓｉｔｉｏｎ1 Ｇ4→ 3Ｈ6 (4 80ｎｍ)ｏｆＴｍ3 ｉｓｉｎｔｈｅｉｎｔｅｒｅｓｔｉｎｇｂｌｕｅｒｅｇｉｏｎ .Ｔｈｅｔｒａｎｓｉｔｉｏｎ3Ｆ4→ 3Ｈ4(～ 1.45 μｍ)ｏｆＴｍ3 ｅｘｈｉｂｉｔｓｃｏｎｓｉｄｅｒａｂｌｅｏｖｅｒｌａｐｗｉｔｈａｎａｂｓｏｒｐｔｉｏｎｂａｎｄｏｆＨ2 Ｏ ,ｓｏｉｔｃａｎｂｅａｐｐｌｉｅｄａｓａｕｓｅｆｕｌｓｏｕｒｃｅｆｏｒｗａｔｅｒｏｒｈｕｍｉｄｉｔｙｓｅｎｓｉｎｇ[1 ] .Ａｈｉｇｈ ｐｏｗｅｒ 1.45 μｍＴｍ3 ｄｏｐｅｄｆｉｂｅｒｌａｓ…     

Energy transfer and mid-infrared luminescence properties of Tm3+ /Dy3+ codoped chalcohalide glasses

A series of chalcohalide glasses based on the composition 0.9 (Ge25 Ga5 S70)-0.1CsI doped with the different Tm3+ / Dy3+ ions ratio were synthesized by melt-quenching technique. The absorption spectra, and mid-infrared fluorescence of different glass samples under 800 nm laser excitation were measured. The results prove that, Tm3+ is an efficient sensitizer, which can enhance the Dy3+ : 2.9 microm fluorescence intensity significantly. A decrease in the intensity of 1.8 microm fluorescence and lifetimes of the Tm3+ : (3)F4 level occurred with increasing the concentration of Dy3+ ions from 0 to 1 Wt% where Tm3+ concentration was fixed to 0.5 Wt%. Also a wide spectral overlap between Tm+ : 1.8 microm emission and the absorption of Dy3+ : 6 H(15/2) --> (6)H(11/2) showed that the effective energy transfer between the two rare-earth ions was mainly attributed to the resonance energy from Tm3+: (3)F4 to Dy(3)+ : (6)H(11/2) level.     

DyxTbyY1-x-yP5O14晶体的荧光性质

研究了DyxTbgY1-x-yP5O14晶体的荧光特征,Dy3+离子对Tb3+离子5D3能级的猝灭作用和对5D4能级的敏化作用,讨论了Tb3+离子和Dy3+离子浓度间的关系及对荧光强度和荧光寿命的影响。     

Yb3+/Ho3+/Tm3+共掺碲酸盐玻璃的上转换白光发射及其机理研究

采用高温熔融法分别制备了Yb3+/Ho3+,Yb3+/Tm3+和Yb3+/Ho3+/Tm3+共掺的碲酸盐玻璃。在980nm红外激光激发下,Yb3+/Ho3+/Tm3+共掺的玻璃样品显示了强的蓝光、绿光和红光发射,分别对应于Tm3+的1 G4→3 H6跃迁、Ho3+的5 F4(5 S2)→5I 8跃迁以及Ho3+的5 F5→5I 8和Tm3+的1 G4→3 F4跃迁。通过对比发现,Yb3+/Ho3+/Tm3+共掺样品中的红、绿光积分发射强度比值(3.95)明显大于Yb3+/Ho3+共掺样品(1.69),这是由于Ho3+和Tm3+间存在交叉弛豫过程3 H4(Tm3+)+5I 6(Ho3+)→3 F4(Tm3+)+5 F5(Ho3+)和3 F4(Tm3+)+5I 8(Ho3+)→3 H6(Tm3+)+5I 7(Ho3+)所致。在激发功率密度为8.2 W.cm-2时,Yb3+/Ho3+/Tm3+共掺样品的上转换发光色坐标值为x=0.345,y=0.338,非常接近于等能白光(x=0.333,y=0.333)。     

LaOBr:Ce,Tb中Ce3+对Tb3+发光的影响

近年来人们对LaOBr:Tb的合成及其发光特性的研究日益增多。LaOBr:Tb不仅是良好的X光增感屏材料,也是较好的阴极射线发光材料。为了进一步提高它的亮度,降低了b的含量(因Tb很贵),寻求LaOBr中Tb3+发光的敏化剂是很重要的。     

ZBLAN玻璃中Nd~(3+),Tm~(3+),Yb~(3+)的上转换发光特性

采用高温固相法制备了Nd,Tm和Yb掺杂的ZBLAN玻璃上转换材料.Tm3+,Yb3+的摩尔浓度分别固定为0.01%,0.3%,Nd3+摩尔浓度变化范围为0.1%～2%.在室温下,测试了样品在300～1 000nm间的吸收光谱.在798 nm近红外光激发下,测试了样品的上转换光谱.实验发现,样品在798 nm红外光激发下发出了较强的多波段(红,蓝和绿)的可见光.由上转换可见光各波段的发射谱线,给出了能级跃迁机制.蓝光主要来源于Tm3+的激发态1G4到基态3H6的跃迁,绿光来源于Nd3+的2H7/2到基态4I9/2的跃迁,红光来源于Nd3+的2H11/2到基态4i9/2的跃迁.研究发现,在Nd3+,Tm3+,Yb3+:ZBLAN玻璃样品中存在激发态吸收,能最转移和交叉弛豫等上转换过程.其发光机理是Nd3+,TM3+和Yb3+离子之间的能量转移.根据Nd3+摩尔浓度不同其上转换发光强度不同,分析了掺入稀土的浓度对上转换发光效率的影响.当Nd3+浓度为1.5%(摩尔分数)时上转换发光最强,大于1.5%后发光开始减弱.     

Tb~(3+)和Ce~(3+)在Sr_7Zr(PO_4)_6基质中能量传递及发光特性研究

用高温固相法制备了Sr_7Zr(PO_4)_6∶Tb~(3+)、Sr_7Zr(PO_4)_6∶Ce~(3+)及Sr_7Zr(PO_4)_6∶Tb~(3+),Ce~(3+)一系列荧光粉,并通过X射线衍射仪及荧光光谱仪分析了其结构和发光性质。结果表明,Sr_7Zr(PO_4)_6∶Tb~(3+)呈现特征绿色发射,最强发射峰位于543 nm,属于Tb~(3+)的5D4→7F5跃迁,激发峰位于226 nm处,但激发带较窄。为拓宽其激发带的宽度,在Sr_7Zr(PO_4)_6∶Tb~(3+)中掺入了Ce~(3+),观察到掺入Ce~(3+)后激发带变宽,且在Ce~(3+)的激发波长处激发得到了Tb~(3+)的发射,表明存在Ce~(3+)到Tb~(3+)的能量传递。