Tm3+掺杂玻璃光纤研究进展

2 μm波段光纤激光可被广泛应用于激光雷达、生物医疗、环境监测以及光谱学等领域,而Tm³⁺掺杂玻璃光纤是2 μm波段光纤激光重要的增益介质。本文从Tm³⁺掺杂玻璃的发光特性出发,介绍了Tm³⁺掺杂玻璃光纤的制备技术,综述了不同玻璃基质材料掺Tm³⁺光纤的研究进展。最后,指出了制备高性能Tm³⁺掺杂玻璃光纤需要解决的关键问题,提出了可能的解决方法,并对Tm³⁺掺杂玻璃光纤发展趋势进行了展望。     

Tm3+/Ho3+共掺碲酸盐玻璃中Tm3+交叉弛豫主导的2.0μm发光特性

研究了不同摩尔分数Tm3 掺杂下Tm3 /Ho3 共掺碲酸盐玻璃在2.0μm处的发光特性.此发光包括两个过程:Tm3 之间的交叉弛豫过程;通过Tm3 与Ho3 之间的能量转移,将能量传递给Ho3 而使Ho3 跃迁至5I7能级上产生布居,当Ho3 跃迁回基态时则发出波长为2.0μm的光.计算了Tm3 的交叉弛豫速率,并根据速率方程分析了Tm3 的交叉弛豫机理.结果表明:随着Tm3 浓度增加,交叉弛豫逐渐增强;2.0μm处发光的强度逐渐增强.证明了在Tm3 /Ho3 共掺情况下,2.0μm处的发光强度取决于Tm3 的交叉弛豫强度.     

Fabrication,tunable fluorescence emission and energy transfer of Tm3+-Dy3+ co-activated P2O5–B2O3–SrO–K2O glasses

A growing demand for white light-emitting diodes (W-LEDs) gives rise to continuous exploration of functional fluorescence glasses. In this paper, Tm³⁺/Dy³⁺ single- and co-doped glasses with composition (in mol%) of 30P₂O₅–10B₂O₃–23SrO–37K₂O were synthesized using the melt-quenching method in air. The physical properties, glass structure, luminescence characteristics and energy transfer mechanism of the glasses were systematically studied. As glass network modifiers, Tm³⁺ and Dy³⁺ ions can densify the glass structure. Excitation wavelength and doping concentration of Tm³⁺/Dy³⁺ ions have a direct impact on the emission intensities of blue and orange light as well as the color coordinate of the as-prepared glasses. A white light very close to standard white light can be obtained under 354 nm excitation when the content of Tm³⁺ and Dy³⁺ is 0.2 mol% and 1.0 mol%, respectively. The results of the emission spectra and decay curves reveal the existence of energy transfer from Tm³⁺ to Dy³⁺. The analytic results based on the Inokuti-Hirayama model indicate that the electrical dipole-dipole interaction may be the main mechanism of energy transfer. Moreover, Tm³⁺/Dy³⁺ co-activated glass phosphor has good thermal stability and chrominance stability and it is a promising candidate for white LEDs and display device.     

Tm3+和Ho3+共掺KYb(WO4)2晶体生长与光谱特性

以K2W2O7作为助熔剂,Yb3+为敏化剂,采用泡生法生长掺8%(摩尔分数,下同)Tm3+和1%Ho3+的Tm,Ho∶KYb(WO4)2(Tm,Ho∶KYbW)晶体.采用X射线衍射(X-ray diffraction,XRD)分析了晶体的结构;测试了晶体的红外光谱和Raman光谱,并对出现的峰值进行了振动归属;测量了晶...     

Tm3+/Ho3+共掺硫系玻璃光纤放大器增益特性

中红外2.0～3.5μm 波段激光在医疗、空气污染监测和军事等领域有着重要的应用前景。采用真空熔融淬冷法制备了 Tm3+/Ho3+共掺的Ge20Ga5Sb10S65硫系玻璃,测试了样品的吸收光谱以及800 nm激光泵浦下的荧光光谱,通过Judd–Ofelt和Mc-Cumber理论计算了Tm3+/Ho3+的辐射寿命、自发辐射几率和受激发射截面等光谱参数。在此基础上,研究了双掺离子之间的能量传递和Tm3+–Ho3+的多种跃迁过程,给出了详细的4能级系统的速率方程,并结合光功率传输方程,得出Tm3+/Ho3+共掺硫系玻璃光纤放大器在2μm波段的增益特性。数值模拟结果表明：Tm3+/Ho3+共掺硫系玻璃光纤在2μm波段的增益值达27 dB,增益带宽为112 nm,最佳掺杂光纤长度L=300 cm,所需泵浦功率Pp=200 mW,可用于2μm波段宽带放大。     

Tm3+掺杂硅酸盐玻璃的1.8μm光谱性质

研究了Tm掺杂硅酸盐玻璃的热稳定性、1.8μm荧光性质.测试了玻璃样品的特征温度、吸收光谱和荧光光谱:根据吸收光谱,计算并讨论了玻璃样品的吸收和发射截面、Judd-Ofelt参数、辐射跃迁几率和辐射寿命等光谱参量.计算得出Tm3+:3F4→3H6能级跃迁的辐射寿命达到5.62ms,受激发射截面和辐射寿命的乘积σem×τ...     

Fabrication of double-cladding Ho3+/Tm3+ co-doped Bi2O3–GeO2–Ga2O3–BaF2 glass fiber and its performance in a 2.0-μm laser

A novel double-cladding Ho³⁺/Tm³⁺ co-doped Bi₂O₃–GeO₂–Ga₂O₃–BaF₂ glass fiber, which can be applied to a 2.0-μm infrared laser, was fabricated by a rod-tube drawing method. The thermal properties of the glass were studied by differential scanning calorimetry. It showed good thermal stability and matching thermal expansion coefficient for fiber drawing when T_x−T_g > 193°C and the maximum difference of the thermal expansion coefficient is 3.55 × 10⁻⁶/°C or less. The 2.0-μm luminescence characteristics were studied using the central wavelength of 808 nm pump light excitation. The results show that when the concentration ratio of Ho³⁺/Tm³⁺ reaches 0.5 mol%:1.0 mol%, the maximum fluorescence intensity was obtained in the core glass, the emission cross section reached 10.09 × 10⁻²¹ cm², and the maximum phonon energy was 751 cm⁻¹. In this paper, a continuous laser output with a maximum power of 0.986 W and a wavelength of 2030 nm was obtained using an erbium-doped fiber laser as a pump source in a 0.5 m long Ho³⁺/Tm³⁺ co-doped glass fiber. In short, the results show that Ho³⁺/Tm³⁺ co-doped 36Bi₂O₃–30GeO₂–15Ga₂O₃–10BaF₂–9Na₂O glass fiber has excellent laser properties, and it is an ideal mid-infrared fiber material for a 2.0-μm fiber laser with excellent characteristics     

Tm3+掺杂Ge-Ga-Se-CsI玻璃中红外发光和增益特性研究

用熔融急冷法制备了系列Tm3+掺杂浓度的Ge-Ga-Se-CsI硫卤玻璃样品,通过测试的吸收光谱和Judd-Ofelt 理论计算了Tm3+离子的强度参数(Ωi,i=2,4,6)、自发辐射跃迁几率(A)、荧光分支比(β)、以及辐射寿命(Trad)等光谱参数.研究了800 nm激光泵浦下样品红外荧光特性与掺杂浓度之间的关系,计算了常温下Tm3+:3 F4→3 H6(1.8 μm)和3H5→3F4(3.8μm)发射截面以及3F4→3H6(1.8 μm)跃迁的增益截面与波长的函数关系.     

Tm3+-Yb3+双掺Li2O-B2O3-SiO2系透明玻璃陶瓷的制备及表征

本文制备了以Li2SiO3为主晶相Li2O-B2O3-SiO2系透明玻璃陶瓷,并研究了B2O3的含量对于玻璃陶瓷结构的影响.利用DSC、XRD和SEM等测试手段进行了表征.以Tm3+/Yb3+共掺作为上转换研究对象,研究了该系玻璃陶瓷的光谱性质.在980 nm激光激发下,Tm3+/Yb3共掺的LBS系玻璃陶瓷中观察到强的474 nm的蓝色、650nm的红色上转换发光,并确定蓝红光均为三光子过程.研究了上转换发光与Tm3+/Yb3+质量比的关系.     

电荷补偿对KSr4(BO3)3:Dy3+,Tm3+发光性能的影响

通过高温固相法制备出单基质KSr4(BO3)3:n%Dy~(3+),0.5%Tm~(3+)(n=0.5,1.0,1.5)白光荧光粉,对356 nm激发的发射光谱进行了测试,发射光谱包含有Dy~(3+)的特征发射峰(491,574 nm),也包含有Tm~(3+)的特征发射峰(454nm)。随着Dy~(3+)掺杂浓度的增加,Tm~(3+)的发光强度逐渐减弱,而Dy~(3+)的发光强度逐渐增强。计算得到KSr_4(BO_3)_3:n%Dy~(3+),0.5%Tm~(3+)(n=0.5%,1%,1.5%)的色温依次为:12 797,7 180,5 734 K。将掺杂浓度为1.5%的补偿电荷Li~+、Na~+和K~+掺入了KSr4(BO3)3:1.0%Dy~(3+),0.5%Tm~(3+)中,发光强度都有明显的增强,补偿电荷为Na~+时KSr_4(BO_3)_3:1.0%Dy~(3+),0.5%Tm~(3+)在574nm处的发光强度最高。通过XRD表征发现掺入Na~+、K~+后基质结构没有明显的改变,Li~+的掺入导致了一个小杂峰的出现。     

Ultraviolet to near-infrared down-conversion in Bi3+–Yb3+ co-doped YAM phosphor

Direct measurements of external quantum yield (QY) were applied to down-converting phosphors of Y₄Al₂O₉ (YAM) co-doped with Bi³⁺ and Yb³⁺. The QY measurements were combined with studies of photoluminescence (PL), photoluminescence excitation (PLE) and photoluminescence decay kinetics. It was found that the energy transfer occurs mainly from one of the four possible types of Bi³⁺ centers in YAM, namely Bi³⁺(I), with excitation and emission maxima at 278 nm and 360 nm, respectively. The absolute QY measurements show large discrepancy between the measured quantum efficiencies of the UV to near-IR down-conversion process and the efficiencies estimated from the shortening of the Bi³⁺ luminescence decay time. Results presented in the paper testify the conversion ratio (which should be 2.0 for an ideal quantum cutting mechanism) to be no more than 1.0 in the studied material.     

Dy3+ doped LiCl–CaO–Bi2O3–B2O3 glasses for WLED applications

Dy³⁺ doped calcium bismuth borate glasses were synthesized in the composition range of xLiCl-(30 − x)CaO-20Bi₂O₃-50B₂O₃ + 1 mol% Dy₂O₃ (x = 0, 2, 5, 7, 10 and 15 mol%, LC0, LC2, LC5, LC7, LC10 and LC15 respectively) using conventional melt-quench technique. Broad XRD profiles confirmed non-crystalline nature of synthesized compositions. The compositional dependencies of structural changes (using FTIR spectra), thermal behavior (using DSC thermographs) and optical band gap (using UV–Vis–NIR spectra) were discussed. Photoluminescence (PL) excitation spectra recorded at 577 nm yielded six different excitation peaks belonging to Dy³⁺ ions. The PL emission spectra recorded at 451 nm were analyzed to extract different light emission parameters viz. Y/B ratio, color coordinates, correlated color temperature (CCT) following CIE 1931 chromaticity diagram. The emission colors were found to lie in white light region and lies very close to standard white light emission. The CCT of sample LC10 (5335 K) is closest to CCT of standard white light (5615 K) which depicted the optimized concentration of LiCl for application of these glasses in WLED application.     

Tm3+离子浓度对碲酸盐玻璃热稳定性及光谱性能的影响

用高温熔融冷淬法制备Tm3+离子掺杂75TeO2-20ZnO-5La2O3碲酸盐玻璃,运用差示扫描量热仪(DSC)分析了玻璃样品的热稳定性,结果表明样品均具有良好的热稳定性.根据紫外-可见-近红外分光光度计测量得到的玻璃吸收光谱,运用Judd-Ofelt理论,计算了Tm3+离子在碲酸盐玻璃中的Judd-Ofelt强度参数、自发辐射概率A、荧光分支比β和辐射寿命ΤR等光谱参数.当掺杂浓度为0.8mol％时,玻璃热稳定性好,3H4的荧光寿命最长,为0.285ms,有望成为一种理想的S波段宽带光纤放大器用基质材料.     

不同掺杂浓度的NaGdF4∶Ho3+,Tm3+,Yb3+发光粉的上转换发光

采用水热法制备了掺杂不同比例Ho3 +/Tmn3+和不同Ylb3+浓度的NaGdF4∶Ho3+,Tm3+,Yb3+上转换发光粉,对其结构和上转换发光性能进行了表征.XRD研究结果表明:所有的样品均为六方结构NaGdF4.980 nm红外光激发下,稀土掺杂的NaGdF4发光粉显示分别来自于Ho3+离子5S2,5F4(Ho)→5I8 (Ho)跃迁发射的绿光,5F5 (Ho)→5I8(Ho)跃迁发射的红光,5 S2,5 F4(Ho)→5I7(Ho)跃迁发射的近红外光;来自Tm3+离子1D2(Tm)→3F4(Tm)和1 G4(Tm)→3H6 (Tm)跃迁发射的蓝光,1 G4(Tm)→3 F4(Tm)跃迁发射的红光,3H4(Tm) →3 H6 (Tm)跃迁发射的红外光.研究了Ho3 +/Tm3比例和Yb3+浓度对发光粉上转换发光性能的影响,并讨论了体系的上转换发光机制.计算的发光粉色坐标显示:掺杂Ho3 +/Tm3+比例和Yb3+浓度的变化能调控样品上转换发光颜色.     

Sc3+/Tm3+/Yb3+共掺六方NaYF4纳米粒子的上转换发光特性

稀土Tm3+和敏化剂(Yb3+)共掺NaYF4是目前发现的Tm3+上转换发光效率最高的材料,但还不能满足实际应用.实验中采用Sc3+/Tm3+/Yb3+共掺Na(Y1-x-y,Tmx,Yby)F4研究不同掺量Sc3+对Tm3+上转换发光效率的影响.用X射线多晶衍射仪和透射电子显微镜分析水热法合成样品的物相结构和晶粒尺寸...     

Upconversion thermal enhancement of 2H11/2→4I15/2 of Er3+ and blue emission of impurity Tm3+ in Sr3(PO4)2:Er3+/Yb3+

A series of Sr_2.99-x(PO₄)₂:.01Er³⁺/xYb³⁺ (x = .02, .04, .06, .08, .10) phosphors in the presence of impurity Tm³⁺ were synthesized by high temperature solid-state method, and X-ray diffraction results show that these samples are pure R-3 m(166) space group phase. The upconversion luminescence (UCL) of Er³⁺ and impurity Tm³⁺ under 980-nm laser excitation were investigated, and the results show that the intense blue UCL of impurity Tm³⁺ and thermal enhancement of ²H_11/2→⁴I_15/2 of Er³⁺ simultaneously exist. When Er³⁺ doping concentration is kept at .01, both the blue UCL intensity of impurity Tm³⁺ and green and red UCL intensity of Er³⁺ reach the maximum at Yb³⁺ doping concentration of .08. The thermal enhancement effect of ²H_11/2→⁴I_15/2 of Er³⁺ was observed as high as 3.27 times from 303 to 723 K, which is because of lattice distortion and phonon-assisted transition. In addition, the optical temperature performance of Sr_2.91(PO₄)₂:.01Er³⁺/.08Yb³⁺ sample was studied, and the maximum absolute temperature sensitivity was calculated as .00623 K⁻¹ at 538 K. This study suggests that Sr₃(PO₄)₂:Er³⁺/Yb³⁺ phosphors in the presence of impurity Tm³⁺ have a promising application prospect as optical temperature sensor at high temperature.     

Ca^2+–Cr^3+共掺杂LaAlO3陶瓷的制备及性能EI北大核心CSCD

采用高温固相反应法,在空气气氛中制备了纯LaAlO3和Ca^2+–Cr^3+共掺杂LaAlO3陶瓷材料,对其在近红外的发射率以及热导率进行了研究比较。结果表明:20%Ca^2+(摩尔分数)和20%Cr^3+掺杂后的La0.8Ca0.2Al0.8Cr0.2O3在0.76~2.50μm的红外发射率达0.92,比纯LaAlO3提高了300%;Ca^2+和Cr^3+的掺杂降低了陶瓷材料的热导率,在1200℃时LaAlO3和La0.8Ca0.2Al0.8Cr0.2O3的热导率最低,La0.8Ca0.2Al0.8Cr0.2O3的热导率最低值为2.602 W·m^–1·K^–1,较纯LaAlO3降低了38%。     

Degradation-controlling mechanisms in natural organic acid solutions of CaO–Al2O3–SiO2–B2O3 glass-ceramics by partially substituting Ca2+ with Ba2+ and Sr2+

The degradation of environmentally friendly CaO–Al₂O₃–SiO₂–B₂O₃ (CASB) glass-ceramics, which consist of anorthite and glass phase, was investigated in three natural organic acid solutions. The results indicated that citric acid had the most significant effect on the degradation of CASB glass-ceramics. While the chemical stability of anorthite is relatively poor, the glass phase also contributed significantly to the effective degradation of CASB glass-ceramics. Subsequently, Ba²⁺ or Sr²⁺ was used for full or partial substitution of Ca²⁺ in CASB glass-ceramics, and the degradation-controlling mechanism of the substituted CASB glass-ceramics was further researched. The full substitution of Ca²⁺ in CASB glass-ceramics by the two cations resulted in the occurrence of borate [BO₄] units in the glass phases, and the interlinkage of [BO₄] with broken silicate [SiO₄] network structures caused a complementary network effect. Consequently, the degradation of CASB glass-ceramics by organic acids was reduced due to the improvements in the chemical stability of the modified glass-ceramics. Additionally, degradation control can also be achieved based on a mixed-alkali effect, originating from the partial substitution of Ca²⁺ in CASB glass-ceramics by Ba²⁺ or Sr²⁺. The degradable glass-ceramics have the potential to be applied in low-temperature co-fired ceramic technology because of their good physical properties, which include a dielectric constant of 3–5, a dielectric loss as low as 10⁻³, a coefficient of thermal expansion of 3–9 × 10⁻⁶/°C, and an average bending strength of about 47 MPa. Noticeably, the development of the degradable glass-ceramics is helpful to the low-cost and pollution-free recycling of valuable metal electrodes, which is significant for the sustainable development of electronic packaging technologies.