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Blue Cooperative Luminescence In Yb3+-Doped Barium Gallogermanate Glass Excited At 976 nm 总被引:1,自引:0,他引:1
The Yb3+-doped barium gallogermanate glass has been prepared via the conventional melt method. The absorption spectra, the near infrared
emission spectra, the upconversion emission spectra and the differential scanning calorimetry have been measured. Bright blue
upconversion emission centered at 476 nm has been observed under the 976 nm laser diode excitation at room temperature. The
blue upconversion emission mechanism has been discussed on the blue emission intensity and the measured lifetime. The slope
of the log-log plot of the blue emission intensity versus the pump power is equal to 1.98, and the blue luminescence decay
time is half of the near infrared fluorescence decay time, confirming that the blue emission comes from Yb3+-Yb3+ pairs cooperative upconversion mechanism. The result of differential scanning calorimetry suggests that this type of glass
is suitable as a potential candidate for fiber drawing. 相似文献
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Abstract Infrared emission spectra emitted by high luminosity infrared pyrotechnics have been observed remotely using the Fourier transform infrared spectroscopy. The primary purpose of the study is to determine infrared spectral radiance distribution, their time—resolved spectra and integrated emission energy. The spectra have been recorded between 4000 – 800cm?1 region with spectral resolution of 4cm?1. The study is very important for many applications. 相似文献
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K. Le Guen M.‐H. Hu J.‐M. André P. Jonnard Z. Wang J. Zhu A. Galtayries C. Meny E. Meltchakov C. Hecquet F. Delmotte 《X射线光谱测定》2011,40(5):338-342
Nanometric Co/Mg, Co/Mg/B4C, Al/SiC and Al/Mo/SiC periodic multilayers deposited by magnetron sputtering are studied in order to correlate their optical performances in the extreme ultraviolet (EUV) range to their structural quality. To that purpose, our recently developed methodology based on high‐resolution X‐ray emission spectroscopy (XES) and X‐ray and EUV reflectometry is now extended to nuclear magnetic resonance (NMR) spectroscopy and time‐of‐flight secondary ions mass spectrometry (ToF‐SIMS). The analysis of the Co Lαβ and Mg Kβ emission spectra shows that the Co and Mg atoms within the multilayers are in a chemical state equivalent to that of the atoms in the pure Co and Mg references, respectively. But NMR spectra give evidence for a reaction between Co atoms and B and/or C atoms from B4C. The Al and Si Kβ emission spectra do not reveal the formation of an interfacial compound in Al/SiC and Al/Mo/SiC. Only the roughness limits the optical quality of Al/SiC. The comparative analysis of the ToF‐SIMS spectra of Al/SiC and Al/Mo/SiC indicates that the structural quality is enhanced when Mo is introduced within the stack. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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To record weak emission spectra, a high-sensitivity diffraction spectrometer, operating in the region 400–1100 nm, has been designed on the basis of a DFS-452 spectrograph and a photodiode reader with a spectral resolution of 0.14 cm?1. A Multiplaz-2500 plasmatron, generating intense molecular emission spectra in the visible and near-IR regions, served as a source of the water vapor emission spectrum at temperatures above 3000 K. Water vapor emission spectra have been recorded for the first time in the range above 10 000 cm?1. The analysis of the spectra obtained has shown that the plasmatron emission spectrum also includes the lines of the OH radical. 相似文献
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The time dependences of the intensity and the energy positions of fine-structure of the spectra of anomalous electron emission
from a polarized lead magnesium niobate (PMN) single crystal irradiated with soft x-rays are investigated experimentally.
It is shown that the relaxation time of the electret charge can be determined from the graphs of these dependences, and the
depth distribution of the potential in the surface layer of the sample can be determined from the profile of the anomalous
electron emission spectrum. Estimates of the fields in the surface layers of a polarized PMN single crystal, obtained from
the characteristics of the anomalous electron emission spectra, agree with data obtained by electrophysical research techniques.
Fiz. Tverd. Tela (St. Petersburg) 39, 1446–1451 (August 1997) 相似文献
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V. S. Belyaev V. I. Vinogradov A. S. Kurilov A. I. Magunov A. P. Matafonov T. A. Pikuz I. Yu. Skobelev A. Ya. Faenov 《Journal of Experimental and Theoretical Physics》2003,96(5):897-903
X-ray emission spectra of the plasma created at the surface of magnesium, aluminum, copper, and zinc targets heated by 1-ps laser pulses with a peak power density of up to 1016 W/cm2 were measured. The effect of a picosecond prepulse on the spectra was studied for various power densities and intensity contrasts of the main laser pulse. It is established that the emission spectra of laser plasmas are weakly affected by a change from 105 to 107 in the main pulse contrast relative to the first prepulse. Variations in the parameters of emission from aluminum and magnesium plasmas were calculated using relative intensities and widths of the resonance lines of H-and He-like ions and their two-electron satellite peaks. 相似文献
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Intense directional light emission from a deformed square-shaped organic light-emitting microring cavity was observed. The ring cavity was a dye-doped organic-inorganic hybrid glass film coated upon a square-shaped fiber. From the near-field and far-field emission patterns and their emission spectra we found, for the first time to our knowledge, the simultaneous existence of chaotic whispering-gallery modes and four-bounce reflection modes. The two types of mode have different emission directions, different lasing thresholds, and different spectral linewidths. High-contrast angle-modulated light emission was also observed. We could control modulation and angular spread of emission by controlling the deformation of the cavity. 相似文献
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掺Yb3+激光玻璃光谱特性研究 总被引:1,自引:0,他引:1
采用高温熔融工艺制备了Yb3 掺杂激光玻璃.测试了玻璃的吸收光谱和发射光谱,计算了Yb3 的积分吸收截面和受激发射截面及荧光寿命等参数.玻璃光谱曲线表明:吸收主峰位于975.35 nm,在900~962 nm范围内有一较为弥散的吸收次峰,中心波长为939.17nm;荧光主峰位于977.15 nm,荧光次峰位于997.42 m;随着样品厚度的增加,荧光次峰强度和荧光主峰强度在增大,荧光次峰波长和荧光主峰波长向长波方向移动;荧光有效线宽从34.64 nm增大到54.50 nm;荧光寿命由1.04 ms减小为1.00 ms. 相似文献
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The emission spectra and its time decay in PbCl2 at low temperature are reported. Three emission bands lying at 3.81 (uv), 2.93 (blue) and 2.60 eV are found for the photo-excitation in the intrinsic absorption region, at 4.2 K. An exponential decay with decay time of 11.4 μs is observed for the uv emission. For the blue emission two kinds of time decay spectra are observed: a second order process below 10 K and an exponential decay above 14 K. The mechanisms of these emission are discussed by taking into account the above results. 相似文献
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针对真空弧离子源,利用条纹相机将时间轴信息转换为空间轴信息的特点,结合光谱仪分光功能,建立了一套高时间分辨与光谱分辨能力的发射光谱诊断装置,其时间分辨率和光谱分辨率分别可达26ps与0.1nm。利用该诊断装置采集获得了单次脉冲内等离子体的时间演化特性;同时,基于局域热力学平衡等离子体的发射光谱理论,建立了一套谱线拟合的等离子体温度与密度计算模型。相比传统的Boltzmann斜率法与Stark展宽法需要寻找孤立的不受附近谱线叠加的干净线状光谱,建立的拟合光谱模型可以直接处理多条谱线因为展宽效应而叠加形成的光谱线型,计算得到等离子体中电子温度与电子密度。结果表明,在脉冲功率源的作用下,真空弧放电等离子体的电子温度与电子密度分别可达1eV与3.5×1024 m-3。 相似文献
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Ya. Zakharko A. Luchechko I. Syvorotka G. Stryganyuk I. Solskii 《Radiation measurements》2010,45(3-6):429-431
Optical absorption, excitation and emission spectra, as well as photoluminescence decay time of CaMoO4 single crystals have been measured. It has been revealed that annealing of crystals in oxygen atmosphere leads to the disappearance of their anisotropic behavior in optical absorption, as well as in X-ray luminescence and decay time. Moreover, it has been found that annealing can significantly affect the value of the decay time. The relative intensity of the long-wavelength emission band increases under excitation in the region of indirect band-to-band transitions. 相似文献
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H. Zhang W. F. Liu P. Wu X. Hai S. Y. Wang G. Y. Liu G. H. Rao 《Journal of nanoparticle research》2014,16(1):1-9
In the present work, we have investigated the effect of deposition time on the morphological, structural, and photoluminescence (PL) properties of β-Ga2O3 NWs grown by CVD technique. The diameter and length of the as-grown NWs varied for the deposition time of 1–4 h, from 50 to 100 nm and 5–15 μm, respectively. The crystalline quality of the NWs improved with increasing the deposition time. The detailed transmission electron microscopy (TEM) and fast Fourier Transformation (FFT) measurements revealed that the as-grown β-Ga2O3 NWs were single crystalline. Furthermore, we have studied the variation of PL spectra of the NWs with deposition time and provided an energy band diagram to give a plausible explanation of the origin of different emissions in the PL spectra. The PL spectra showed a broad strong UV-blue emission band and a weak red emission for 1 h deposited sample. We suggested that the UV and red emission from β-Ga2O3 NWs are related to oxygen vacancies and impurities such as nitrogen, respectively. It was observed that the intensity of UV emission decreased with deposition time and this reduction was attributed primarily to the reduction of oxygen vacancies in the NWs. 相似文献
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Hui-ding Xie Louisa A. Ho Michael S. Truelove Ben Corry Scott G. Stewart 《Journal of fluorescence》2010,20(5):1077-1085
In this paper we describe a semi-empirical quantum method for predicting the wavelength of maximum fluorescence excitation
and emission for several known and new maleimide derivatives. All new maleimides, containing a N-Benzyl attachment, were successfully synthesised via a tandem Suzuki reaction with aryl boronic acids containing either an electron donating, electron withdrawing functional
groups. Absorption and emission spectra calculated using the semi-empirical AM1 method with excited state ZINDO calculations
proved more reliable than either Hartree-Fock Configuration interaction or time dependent density functional methods. Calculated
absorption and emission wavelengths were compared with 26 experimental spectra from known or newly synthesised maleimides
and found to have provide reasonable predictions, with an average deviation of less the 6% for absorption maxima and less
than 4% for emission peaks. The described method provides a strong benchmark for the accuracy that can be expected from theoretical
predictions of fluorescence spectra. 相似文献
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Eu^3+掺杂SiO2气凝胶薄膜的时间分辨光谱及发光动力学 总被引:1,自引:0,他引:1
气凝胶(aerogels)是一种新型的轻质纳米多孔性非晶材料,其孔洞率高达80~90%,孔洞的典型尺寸为1~100nm.已有文献报道利用SiO2气凝胶的纳米网络结构制备出以纳米气凝胶为骨架的纳米材料[1~2].通过溶胶-凝胶方法制得了Eu3+掺杂Si... 相似文献
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Magnesium oxide nanowires (NWs) were synthesized by a current heating process. The effect of annealing treatment in air on their structural and optical characteristics was investigated. As-grown NWs in diameter ranging from 30 to 70 nm and length up to several 10 μm were obtained. Carbon-coating layers were observed in the as-grown NWs which were oxidized during the annealing treatment at high temperature. Ionoluminescence spectra of the as-grown and annealed NWs have showed two emission peaks centered at 360 nm (UV emission) and 492 nm (green emission). The intensities of green emission were maximum at the annealing temperature of 650 °C for 2 h, whereas those of UV emission were decreased with increasing the annealing temperature. It is anticipated that maximum green emission correlates to the sufficient density of oxygen vacancies which was occurred by the optimum annealing parameters of both temperature and time. 相似文献
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In this paper we present and discuss results of detailed spectroscopy studies of Pr3+ luminescence from the (Ba,La)F2:0.2 m%Pr crystals under UV and VUV synchrotron excitation.We have measured time resolved emissions from the minor site Pr3+ in (Ba,La)F2:Pr at 10 and 300 K. The spectra clearly show the 1S0 emission from the Pr3+ ions in some low symmetry Pr-sites (we designate them La-sites) previously identified in higher concentration (0.3 m%Pr and more) crystals. However most of emission from the Pr activated (Ba,La)F2 crystals originates in Pr3+ ions in other sites which produce an efficient d-f emission. As demonstrated by excitation spectra, the emission from some of these sites (denoted as Ba-sites) closely resembles the d-f emission from BaF2.The La-site, time resolved and long delay emission spectra are dominated by hypersensitive transitions from the 1S0 and 3P0 levels to lower energy levels of the 4f2 configurations. Only these transitions contribute to the photon cascade emission desired for some mercury free phosphor applications. 相似文献
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掺Er3+钆硼硅酸盐玻璃及玻璃陶瓷的红外发光特性和热稳定性 总被引:3,自引:0,他引:3
报道了一种新型可作为掺铒光纤放大器(EDFA)基质材料的Er3+掺杂B2O3-SiO2-Gd2O3-Na2O(BSGN)体系玻璃及其玻璃陶瓷。对材料中铒的4I13/2→4I15/2跃迁的1.5μm发射光谱、吸收光谱、时间分辨光谱及寿命进行了测量和分析,讨论了热处理对玻璃材料带宽和寿命的影响。结果表明,铒掺杂玻璃1.5μm发射的带宽和J-O参数Ω6都随B2O3含量的增加而增加,寿命随B2O3含量的增加而减小。经过热处理后得到的玻璃陶瓷比具有相同组分的玻璃具有更高的1.5μm发射效率。同时,差热分析的数据表明,该玻璃体系具有极好的热稳定性。 相似文献