Tm3+/Ho3+共掺碲酸盐玻璃的2.0μm发光特性及能量传递

研究了Tm³⁺/Ho³⁺共掺TeO₂-WO₃-ZnO玻璃在808 nm激光二极管抽运下的2.0μm发光特性及Tm³+与Ho³⁺之间的能量传递.应用Judd-Ofelt理论计算了Ho³⁺在碲酸盐玻璃中的谱线强度参量Ω_t (t=2,4,6)、自发辐射概率A_r、辐射寿命τ_r等.计算了Ho³⁺的吸收截面σ_a(λ)和受激发射截面σ_e(λ).结果表明：碲酸盐玻璃中Tm³⁺→Ho³⁺正向能量传递系数大约是Tm³⁺←Ho³⁺反向能量传递系数的18倍.Ho³⁺离子的⁵I₇能级的寿命为3.9ms，2.0μm处的最大发射截面为9.15×10^-21cm².在0.5mol% Tm₂O₃和0.15mol% Ho₂O₃共掺的碲酸盐玻璃中能获得2.0μm的最大增益.通过比较氟化物、碲酸盐和镓铋酸盐重金属氧化物等玻璃中Ho³⁺的量子效率η，σ_e×τ_m值和增益系数G(λ)等，发现Tm³⁺/Ho³⁺共掺碲酸盐玻璃是一种理想的2.0μm激光器用基质玻璃. 关键词： 2.0μm发光 能量传递 增益 碲酸盐玻璃     

单频光纤激光器研究进展

单频光纤激光器在激光武器、激光雷达、空间激光通信、相干光通信、高精度光谱测量、引力波探测等领域有着广泛的应用前景,受到了研究者的极大关注.从1.0,1.5,2.0μm三种典型工作波段进行归类,综述了单频光纤激光器的国内外研究现状,内容涵盖了单频光纤激光产生、噪声抑制、线宽压窄、连续与脉冲单频激光放大等技术.此外,结合了...     

Empowering perovskite PbTiO3 nanoparticles with enhanced up-conversion luminescence and thermal sensitivity by introducing Er3+ dopant

Up-convertion(UC)perovskite Er³⁺-doped Pb TiO3(Er-PTO)nanoparticles with green and red emissions were synthesized via the hydrothermal method.The UC properties were manipulated by adjusting the concentration of Er³⁺ ions dopant.The green emission intensity was decreased as the doping concentration increased from 1% to 4%(mole fraction),whereas the red emission intensity was increased.The influences of Er³⁺ ions on the temperature-sensing performance were further investigated.The results demonstrated that Er-PTO nanoparticles with doping 1% Er³⁺ ions possessed a sensitivity of3.1×10^-3 K^-1 at 475 K,presenting a high potential in optical heating devices.     

高基体样品进样系统-电感耦合等离子体质谱法测定进口铜精矿中稀土元素的含量

铜精矿的铜含量在20%～30%,是冶炼铜的基础矿物原料，由于地质因素和冶炼技术的差别，世界各矿区铜精矿的等级存在差异，加之近年来，铜精矿掺假造假、伪报瞒报、有毒有害元素超标等案件多发，对国家和人民的生活和经济发展造成了危害，建立进口铜精矿产地溯源和特征成分分析方法，在口岸执法方面可以提供有效技术支持。本研究应用电感耦合等离子体质谱仪测定铜精矿样品中的钇、镧、铈、镨、钕、钐、铕、钆、铽、镝、钬、铒、铥、镱、镥等15种稀土元素含量。铜精矿的物理化学性质相对稳定，针对铜精矿中稀土元素的消解方法有碱熔法、微波消解酸溶法和常压酸溶法，实验采用改进的常压酸溶法对样品进行消解，选取具有代表性的5^#, 6^#, 13^#, 16^#和18^#不同稀土元素含量的铜精矿样品，通过对氢氟酸、高氯酸、勒福特王水三种强酸的加入顺序和用量进行试验，得到了所有铜精矿样品能够完全溶解，而且用量合理的混合强酸体系最佳方案为3 mL氢氟酸-1 mL高氯酸-3 mL勒福特王水。铜精矿属于高基体样品，其硅酸盐、碳酸盐等高盐化...     

Er^3＋/Tm^3＋/Yb^3＋ tridoped oxyfluoride glass ceramics with efficient upconversion white-light emission

A novel Tm^3＋/Yb^3＋ triply-doped glass ceramics containing BaF2 nano-crystals are successfully prepared. Fluoride nanocrystals BaF2 are successfully precipitated in glass matrix, which is affirmed by the X-ray diffraction results. The intense blue （476 nm）, green （543 nm）, and red （656 nm） emissions of the glass ceramics are simultaneously observed at room temperature under 980-am excitation, and the emission luminescence intensity increases significantly compared with the precursor glass, which is attributed to the low phonon energy of fluoride nanocrystals when rare-earth ions are incorporated into the precipitated BaF2 nanocrystals. Under 980-nm excitation at 400 mW, the international commission on illumination （CIE） chromaticity coordinate （X = 0.278, Y = 0.358） of the tridoped oxyfluoride glass ceramics＇ upconversion emissions is close to the standard white-light illumination （X = 0.333, Y= 0.333）. The results indicate that Tm^3＋/Yb^3＋ triply doped glass ceramics can act as suitable materials for potential three-dimensional displays applications.     

Amplified spontaneous emission properties of a single mode Er~(3+)-doped tellurite fiber

Spectral characteristics of the amplified spontaneous emission (ASE) from a novel single mode Er~(3+) doped tellurite fiber with D-type cladding is reported in this letter. When pumped at 980 nm, an ASE source that has nearly a 100-nm flat FWHM bandwidth is obtained with a fiber length of 30-60 cm. Variation of ASE spectra with pump powers and fiber lengths are measured. Output power up to 2.0 mW is obtained with a launched pump power of 660 mW.     

Broadband Near-Infrared Emission from Transparent Ni^2＋ -Doped Sodium Aluminosilicate Glass Ceramics

Broadband near-infrared emission from transparent Ni^2＋-doped sodium aluminosilicate glass-ceramics is observed. The broad emission is centred at 1290nm and covers the whole telecommunication wavelength region （1100- 1700hm） with full width at half maximum of about 340hm. The observed infrared emission could be attributed to the 3T2（F） → 3A2（F） transition of octahedral Ni^2＋ ions that occupy high-field sites in nanocrystals. The product of the lifetime and the stimulated emission cross section is 2.15 × 10^-24 cm^2s. It is suggested that Ni^2＋- doped sodium aluminosilicate glass ceramics have potential applications in tunable broadband light sources and broadband amplifiers.     

荧光捕获效应对Yb3+磷酸盐玻璃光谱性质的影响

测试了不同掺杂浓度和不同厚度下Yb3+ 磷酸盐玻璃的吸收光谱、荧光光谱和荧光寿命 ,计算了积分吸收截面、吸收截面、受激发射截面、自发辐射寿命以及荧光有效线宽等光谱参数 ,讨论了荧光俘获效应对Yb3+ 磷酸盐玻璃光谱性质的影响 .结果表明荧光俘获效应随样品厚度和掺杂浓度的增加而增大 .由于荧光俘获效应的存在使得测量的Yb3+ 磷酸盐玻璃荧光寿命明显长于计算的荧光寿命 ,在 0 2mol%Yb2 O3低掺杂浓度下采用不同厚度 ( <4mm)的样品测量的荧光寿命之间误差为 3 0 %左右 ,高浓度 ( 6mol%Yb2 O3)掺杂下误差可达 43 % .荧光俘获还造成荧光谱线加宽 ,导致荧光有效线宽在低浓度 ( 0 2mol%Yb2 O3)时增加 14% ,在高掺杂浓度 ( 6mol%Yb2 O3)下增加 3 0 %以上     

Tb^(3+)掺杂透明锗酸盐微晶玻璃:制备与面向X射线探测的增强发光EI北大核心CSCD

通过熔融淬火和后续热处理,成功制备了Tb^(3+)掺杂含LaF_(3)纳米晶透明锗酸盐微晶玻璃。详细研究了所制备的玻璃和微晶玻璃的发光性质。X射线衍射结果表明,玻璃基体中析出的晶相为纯LaF_(3)晶体,晶粒尺寸在16~21 nm之间。在377 nm紫外光和X射线激发下,Tb^(3+)掺杂含LaF_(3)纳米晶的微晶玻璃比Tb^(3+)掺杂的锗酸盐玻璃表现出更强的绿光发射,且绿光发射强度随热处理温度升高和时间的延长而增强。微晶玻璃在X射线激发下的最大积分发光强度约为商用闪烁晶体Bi_(4)Ge_(3)O_(12)的40.3%。本研究表明,掺Tb^(3+)含LaF_(3)纳米晶锗酸盐微晶玻璃在X射线探测中具有潜在的应用前景。     

基于声光偏转的高速GHz超快激光扫描技术

双光子激发显微镜是研究脑神经元活动的重要工具。基于传统机械式逐点激光扫描技术的双光子激发显微镜成像速度较慢,无法进行脑神经元活动的实时观察研究。此外,高速双光子激发显微成像需要配置高重复频率飞秒激光,以保证在较短的像素停留时间内获得较高的信息强度。本文提出了基于声光偏转的并行GHz超快激光扫描技术,通过设计射频编码方案,在920 nm波段搭建了高速GHz超快激光扫描系统。通过调整时间和空间重合,最终在15～31 MHz频率范围内获得了33个可分辨的并行GHz超快激光扫描光束,为实现高速双光子激发显微成像提供了技术支撑。