Fabrication and photoluminescence characteristics of nonuniform Yb-Er codoped films

The nonuniform Yb-Er Codoped Al2O3 films were prepared on SiO2/Si substrates using a medium frequency magnetron sputtering system. Two asymmetry targets in the system were introduced to realize the nonuniform dopant. Some curves of Photoluminescence （PL） peak intensity were obtained by adjusting the deposition parameters, such as, the pillar number of erbium and ytterbium in the mixed target and the distance between a sample table and targets. Typically, the curve of PL peak intensity against the offset distance was approximately linear. The ratio of the PL intensity at the two ends of the same sample was 12.6 and the slope was 71.83/mm when the pillar numbers of the erbium and ytterbium in the mixed target are 5 and 60, respectively, and the distance between targets and the sample table is 2.9 cm.

Phase transformation and morphology tuning of β-NaYF_4:Yb^(3+),Er^(3+) nanocrystals through K^+ ions codoping

In this work, a simple method to modulate the crystal phase and morphology with a large amount of K＋ions codoping is proposed. The phase changes to the mixture of β-Na YF4 and β-KYF4 with increasing the content of K^＋ions to 80 mol%.When it exceeds 80 mol%, β-Na YF4 disappears gradually and β-KYF4 dominates with a poor crystalline. In addition, the morphology changes from nanosphere to nanoplate, and then to nanoprism, which indicates that a higher content of K^＋ions favors the growth rates along [0001] than the [10-10] of the nanocrystals. Additionally, the upconversion（UC） luminescence properties and the ratio of red/green（R/G） UC intensity of samples with different phases and morphologies are detected,which makes it possible to tune the UC fluorescence by varying the concentration of K^＋ions.

氟氧化物玻璃中稀土ErYb与HoYb能量上转换特性研究

在特定恒温环境下烧结Er与Yb ,Ho与Yb共掺杂氟氧化物两样品。用 930nm激光激发 ,测得两样品的发射荧光光谱 ,发现两样品发射荧光光谱中都分别有红光带和绿光带。由Er2 O3 ,Ho2 O3 ,Yb2 O3

Ho^(3+)单掺杂及其与Yb^(3+)、Er^(3+)共掺杂硼硅酸盐玻璃上转换发光的光谱分析

采用高温固相烧结法制备了Ho^(3+)单掺杂、Ho^(3+)/Yb^(3+)共掺杂、Ho^(3+)/Er^(3+)共掺杂和Ho^(3+)/Yb^(3+)/Er^(3+)共掺杂等系列硼硅酸盐玻璃,测量了样品的激发光谱和发射光谱。结果表明:Ho^(3+)单掺杂样品的激发光谱与发射光谱的强度随其浓度增加而逐渐减弱,原因是高浓度掺杂导致Ho^(3+)离子产生猝灭效应;Ho^(3+)/Yb^(3+)共掺杂玻璃由于Yb^(3+)离子的敏化作用,光谱强度增强;Ho^(3+)/Yb^(3+)/Er^(3+)共掺杂样品中Ho^(3+)离子向Er^(3+)离子发生能量传递,Ho^(3+)离子的激发光谱和发射光谱强度均减弱。同时讨论了峰值波长为550nm宽带发射峰的发光机制。

Simulation of High Power Er/Yb Codoped Fiber Linear Cavity Lasers

The performances of high power Er/Yb codoped fiber linear cavity lasers are investigated numerically. The numerical analysis is based on the iterative solution of rate equations for population density of the Er/Yb ions. The behaviors of co-pump and counter-pump methods are contrasted. Dependence of output power on input pump power, output reflectivity, operating wavelength and active fiber length is simulated, respectively. High conversion efficiency Er/Yb laser output is obtained in simulations and experiments.

Er^(3+)/Yb^(3+)共掺光纤激光器中能量上转换的抑制

通过对掺Er3+和Er3+/Yb3+共掺光纤激光器的输出功率进行数值模拟发现 :高浓度的Er3+/Yb3+共掺光纤激光器的最大量子转换效率比同等浓度下的掺Er3+光纤激光器的最大量子转换效率高出一倍。说明由于Yb3+的加入 ,Er3+/Yb3+共掺光纤激光器有效地抑制了能量上转换 。

Na_2SiF_6对Er^(3+),Yb^(3+)共掺杂上转换发光材料颗粒度的影响

合成了Er3+,Yb3+共掺杂的纳米级上转换发光材料。针对稀土离子Er3+,Yb3+共掺杂上转换发光材料的制备过程,研究了络合剂和Na2SiF6对控制最终产物颗粒度的作用,指出络合剂和Na2SiF6的共同作用有利于合成出粒度分布比较均匀的纳米级上转换发光材料,讨论了Na2SiF6的作用机制,并简单阐述了上转换发光材料的发展和应用。

Er^(3+)/Yb^(3+)共掺杂纯氧化物材料上转换发光特性的研究

对实验制备的Er3+/Yb3+共掺杂3CaO-Al2O3-3SiO2样品在980激发下的上转换发光特性进行了研究,检测到由处于激发态能级2H11/2,4S3/2和4F9/2的Er3+离子分别向基态4I15/2跃迁时发出的波长依次为523,547和656 nm的上转换发光。做出了上转换发光强度与激发功率关系的曲线图,并结合测得的声子能量对相应跃迁机制进行了分析,发现上转换过程中Yb3+对的敏化作用起主要作用。

Yb^(3+)/Er^(3+)共掺杂TeO_2-WO_3-ZnO玻璃的光谱性质

制备了Yb3+/Er3+共掺杂的TeO2 WO3 ZnO玻璃,测量了Er3+在玻璃中的吸收光谱和970nmLD激发下的荧光光谱、荧光寿命和上转换光谱。计算了Yb3+/Er3+间的能量传递效率和Er3+离子1.5μm波段的吸收截面、发射截面,并研究了其荧光强度和上转换发光与Yb3+掺杂浓度间的关系。结果表明,Yb3+共掺杂可明显提高Er3+离子1.5μm发射的荧光强度,实验所得Yb3+离子的最佳掺杂浓度为Er3+离子浓度的3倍,在7.28×1020ions/cm3左右。Er3+离子1.5μm发射的荧光半峰全宽为67～72nm;上转换红、绿光均为双光子过程,随Yb3+掺杂浓度的增加,上转换红、绿光强度均增强。

Er^(3+)/Yb^(3+)共掺碲钨酸盐玻璃的热稳定性和1.5μm波段的光谱性质(英文)

制备了Er3 +/Yb3 +共掺的碲钨酸盐玻璃样品,TeO2-WO3-RmOn(RmOn=PbO,BaO,La2O3,Bi2O3),研究了样品的热稳定性和1.5μm波段的光谱性质。碲酸盐中引入WO3的目的是为提高基质的声子能量,使Er3 +离子4I13/2→4I15/2的多声子弛豫速率增加,从而提高4I13/2能级上的Er3 +离子数,这对提高1.5μm处的荧光强度有利,另外加入WO3也能提高碲酸盐玻璃的抗析晶能力。测试了样品的FT-IR光谱,发现碲钨酸盐玻璃样品中存在着TeO4、TeO3、WO4和WO6结构体。周围环境的不对称性导致Er3 +在1.5μm处的光谱有非均匀的展宽和大的受激发射截面。Er3 +在70TeO2-20WO3-10Bi2O3玻璃中4I13/2→4I15/2能级发射的荧光半峰全宽(FWHM)为77 nm,应用McCumber理论计算的受激发射截面(σpeak)为1.03×10-20cm2。其FWHM×σpeak乘积远大于掺Er3 +的铋酸盐、磷酸盐、碲酸盐和硅酸盐玻璃,说明碲钨酸盐玻璃是一种制备宽带光纤放大器优良基质材料。

Er^(3+)和Yb^(3+)共掺氟氧化物微晶玻璃的研究

制备了Er3+、Yb3+共掺的SiO2-Al2O3-PbF2-CdF2系统玻璃,并进行相应的微晶化热处理,研究了氟氧化物微晶玻璃中Er3+离子的上转换发光特性.研究结果表明:原始玻璃经热处理后得到的β-PbF2相氟氧化物微晶玻璃,Er3+和Yb3+所在局域基质声子能量的降低,使微晶玻璃中Er3+上转换发光强度显著提高,而微晶化后Er3+、Yb3+离子局域环境发生变化,导致微晶玻璃中Er3+离子的绿光上转换荧光强度较强,而红光上转换荧光强度相对较弱.

Er^3＋-Yb^3＋共掺杂光纤环型腔被动谐波锁模激光器

报道了Er3+-Yb3+共掺杂光纤作为增益介质的环型腔光纤激光器。利用光纤的非线性偏振旋转效应产生可饱和吸收体的锁模机制,通过调整泵浦功率,调节偏振控制器的状态,实现了连续基波锁模和高阶谐波锁模两种稳定的锁模运转状态。其中连续基波锁模重复频率15.89 MHz,中心波长为1.557 nm,光谱宽度为9.9 nm。二阶谐波锁模重复率为31.79 MHz,三阶谐波锁模脉冲重复率为46.99 MHz。观察到了调Q锁模和调Q脉冲序列,给出了各种运转状态的实验结果并对多种锁模机理作了简要的分析。

Er/Yb双掺杂Li_6Y(BO_3)_3晶体的偏振光谱性能

采用提拉法生长得到了Er/Yb双掺杂的Li6Y(BO3)3晶体,测定了晶体中实际的Er3+和Yb3+离子浓度,在室温下记录了晶体的偏振吸收和发射光谱,测定了1 030 nm和1 535 nm处的荧光衰减曲线,并计算了Yb3+与Er3+离子间的能量传递效率。相比于Er3+离子单掺杂Li6Y(BO3)3晶体,Er/Yb双掺杂晶体在1 000nm附近处的吸收明显增强,在1 550 nm波长附近宽达200 nm的宽带发射以及Yb3+与Er3+离子之间有效的能量传递表明Er/Yb双掺杂的Li6Y(BO3)3晶体是一种潜在的可用于可调谐及超短脉冲激光的介质。

纳米Ag薄膜增强Er^(3+)/Yb^(3+)共掺Al_2O_3薄膜上转换发光特性研究

采用射频磁控溅射在石英基底上制备Al_2O_3:Er^(3+)/Yb^(3+)薄膜,在其表面采用直流磁控溅射沉积纳米Ag薄膜。上转换发光测试表明在491和678 nm的发射峰出现了5.8倍和5.2倍的增强。X射线衍射、原子力显微镜以及透射﹑吸收和散射光谱表明:491 nm发射增强主要源于局域表面等离子或表面等离子与发射带的共振耦合辐射机制,而678 nm发射增强主要源于纳米Ag膜对荧光的LSP散射机制。

Determination of energy transfer and upconversion constants for Yb^(3+)/Er^(3+) codoped phosphate glass

The energy transfer and cooperation upconversion processes are investigated in Yb3＋/Er3＋ codoped phos- phate glass. Based on the measured curves of output power versus incident power, the laser and spectroscopic parameters of the glass are fitted and analyzed. We focus on the resonant energy transfer constant k from Yb3＋ to Er3＋ as well as the cooperation upconversion coefficient Cup from 4113/2 of Era＋. The fitted k and Cup can give almost the same results for different thicknesses of glass disk with the same dop- ing concentrations. The determination of these parameters is helpful for the development of Yb3＋/Er3＋ codoped laser glass.

Enhanced 1-5 μm near-and mid-infrared emission in Ho/Ybcodoped TeO-ZnF oxyfluorotellurite glasses

Intense 1-5 μm infrared emission from near-to mid-infrared was obtained from Ho3+/Yb3+codoped TeO2-ZnF2 oxyfluorotellurite glasses which were prepared by melt-quenching method under the 980 nm LD excitation,and the emission intensity can be enhanced with the increase of ZnF2 content.Judd-Ofelt analysis was used to evaluate the radiative transition parameters of the excited levels according to the absorption spectra.The stimulated emission cross section of 5 I6→5 I8(1.2 μm),5 I7→5 I8(2.0μm),5 I6→5 I7(2.85 μm) and 5 I5→5 I6(4.0 μm) transitions were calculated to reach 0.639 × 10-20,0.760 ×10-20,0.985×10 20 and 0.484 × 10-20 cm2,respectively.The energy transfer coefficients(CDA) are enhanced with the increase of ZnF2 content and phonon contribution ratios of phonon assisted energy transfer process between Ho3+ and Yb3+were figured out.Our results demonstrate that these TeO2-ZnF2 glasses,which possess good thermal stability and transparency,low phonon energy(about 600 cm-1),excellent near-and mid-infrared emission in the range of 1-5 μm wavelength,would be promising material for infrared optical fibers and infrared lasers.

Yb^(3+)/Er^(3+)-Codoped Tungsten-Tellurite Glasses for Broadband Optical Amplifier

Emission spectra and fluorescence lifetime of Er3+ in Yb3+/Er3+-codoped tungsten-tellurite glasses were measured. Effects of Yb3+concentration on 1.5μm emission intensity and bandwidth of Er3+ were investigated and a FWHM of 81 nm was demonstrated.

Yb^(3+)敏化的Er^(3+)/Ho^(3+)共掺碲酸盐玻璃的上转换发光研究

用高温熔融法制备了系列Er3+/Yb3+共掺,Ho3+/Yb3+共掺,和Er3+/Yb3+/Ho3+三掺碲酸盐玻璃,在975nm激光抽运下三种掺杂玻璃中都出现了较强的绿光和红光上转换.研究了Yb3+离子对Er3+和Ho3+离子上转换发光强度的影响以及Yb3+→Er3+,Yb3+→Ho3+能量传递效率.分析了碲酸盐玻璃中Yb3+直接敏化Er3+,Ho3+上转换发光机理.当Er3+和Ho3+浓度较低时,Er3+/Yb3+/Ho3+三掺玻璃的上转换强度随着Yb3+离子浓度的增加而增强,出现的548nm绿光和660nm红光主要是由于Er3+:4S3/2→4I15/2,Ho3+:5F4(5S2)→5I8和Er3+:4F9/2→4I15/2,Ho3+:5F5→5I8跃迁共同作用的结果.Er3+/Yb3+/Ho3+三掺碲酸盐玻璃的上转换机理受Er3+/Yb3+之间,Ho3+/Yb3+之间,Er3+/Ho3+之间三者共同相互作用影响,Er3+/Ho3+离子间存在的交叉弛豫过程可增加Ho3+离子在可见光范围的上转换强度.

Er^(3+)/Yb^(3+) Codoped Phosphate Glass for Ion-Exchanged Planar Waveguide Amplifiers

A novel Er3+/Yb3+ codoped phosphate glass was developed, which exhibited good chemical durability in molten salts and excellent spectroscopic properties. Preliminary results of ion exchange at different time and temperature, and with varying melt concentrations indicated that WM4 glass was suitable for ion-exchange experiments and there was no deterioration of surface quality.

热解法制备KY_3F_(10):Yb,RE(RE=Er,Ho,Tm)纳米晶及其特性研究

有机染料和量子点等荧光标记材料存在发射光谱宽、光热稳定性差和细胞毒性等缺陷,限制了其在生物学研究中的应用.镧系掺杂上转换发光材料不存在'自发荧光'和'光漂白'现象,灵敏度高,长期稳定性好,利于活体检测.论文首次采用热解法,以油酸和十八烯为表面活性剂和溶剂,制备了KY_3F_(10):Yb,RE(RE=Er,Ho,Tm)纳米晶.研究了油酸含量对产物形貌和粒径尺寸的影响,当油酸与十八烯的比例为3:1时,为制备类球形单分散纳米晶体的最佳工艺条件,在980 nm半导体激光器激发下,样品KY_3F_(10):Yb,RE(RE=Er,Ho,Tm)分别发射出较强的黄绿、绿色和蓝色光,这些结果显示KY_3F_(10):Yb,RE(RE=Er,Ho,Tm)纳米粒子作为生物探针在多重荧光标记方面具有优异的特性.