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In the present work, the photoluminescence (PL) spectra of bismuth germanate (BGO) doped with trivalent rare earth element (REE) ions with different doping concentrations (0.03 wt% Eu, 0.4 wt% Tm, and 1.1 wt% Nd) are reported in the temperature range from 10 to 300 K using different detectors, namely, photomultiplier tube (PMT), InGaAs (IGA), and Si. The luminescence in the NIR region was also measured at room temperature. Two broad emission bands attributed to undoped BGO were found at circa 1350 and 1800 nm, respectively. The broad-band emissions are replaced by narrow-band line emissions defined by the trivalent rare earth dopants. The emission spectra from rare earth ion–doped BGO extend from 500 to 2000 nm. Rare earth ions act as the dominant recombination centers and define the emission spectra. This is interpreted as resulting from direct charge transfer from intrinsic defect traps to rare earth recombination centers. The temperature-dependent luminescence of BGO doped with 0.4 wt% Tm is also presented. 相似文献
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OH− and Cl− doped Bi4Ge3O12 (BGO) single crystals had been grown by Vertical Bridgman (VB) method. The structure of these crystals was determined by XRD, the transmittance and emission spectra in near infrared region (NIR) were measured at room temperature. 5% OH− doped BGO shows a significant emission band peaking around 1181 nm under 808 nm laser diodes (LDs) excitation, and the 5% Cl− doped BGO exhibits a relatively weak emission band as well. 100% and 5% OH− doped BGO show noticeable emission band centered at about 1346 nm under 980 nm LDs excitation. 相似文献
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OH− doped and Bi-rich Bi4Ge3O12 (BGO) single crystals were grown by Vertical Bridgman (VB) method. The structure of these crystals was determined by XRD, and the emission spectra in visible and near infrared region (NIR) were measured at room temperature. The emission spectrum of Bi-rich BGO has extra peaks at 385, 367 and 357 nm, Bi-rich BGO after annealing in Ar at 500 °C for 5 h shows a significant emission band peaking around 1170 nm under 808 nm laser diodes (LDs) excitation, and OH− doped BGO shows a noticeable emission band centered at about 1346 nm under 980 nm LDs excitation. A brief discussion is presented. 相似文献
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The major components PbO and WO3 in PWO crystals, Bi2O3 and GeO2 in BGO crystals, as well as Gd, La, Nb, Mg, Mo, Bi, Sb and Y doped in PWO crystals and Eu doped in BGO crystals were successfully determined with X‐ray fluorescence spectroscopy (XRF) using fusion techniques. Calibration standards were synthesized with high‐purity oxides and standard solutions. The analysis results can meet the general requirements of the quality control of the crystal growth and research purpose. The relative standard deviations for Bi2O3, GeO2, PbO and WO3 are 0.21%, 0.18%, 0.25% and 0.22%, respectively (k = 8). The detection limits for dopants in PWO are below 5 µg/g for Gd, La, Nb, Mo, Sb and Y and below 20 µg/g for Mg and Bi. The detection limits for Eu doped in BGO are 8 µg/g. The testing results of XRF were compared with those of inductively coupled plasma optical emission spectroscopy. It was found that the relative differences of the testing results between the two methods are less than 10% for most dopants in PWO crystals. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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采用高温熔融法制备Ce~(3+)或Tb~(3+)单掺和Ce~(3+)/Tb~(3+)共掺钆-钡-硅酸盐闪烁玻璃。通过透射光谱、光致激发和发射光谱、X射线激发发射光谱及荧光衰减曲线等手段对其发光性能进行研究。实验结果表明:在紫外光的激发下,Tb~(3+)掺杂闪烁玻璃发出明亮的绿光(544 nm),而Ce~(3+)掺杂闪烁玻璃发出蓝紫光。对于Ce~(3+)/Tb~(3+)共掺闪烁玻璃,在紫外光和X射线激发下均观察到Ce~(3+)离子敏化Tb~(3+)离子发光的现象,这是由于存在Ce~(3+)→Tb~(3+)的能量转移。Ce~(3+)/Tb~(3+)共掺闪烁玻璃的最佳Ce2O3掺杂摩尔分数为0.2%,此时Ce~(3+)离子向Tb~(3+)离子的能量传递效率为45.7%。在X射线激发下,Ce_2O_3摩尔分数为0.2%的Ce~(3+)/Tb~(3+)共掺闪烁玻璃在544 nm处的发光强度是Bi_4Ge_3O_(12)(BGO)闪烁晶体在500 nm处发光强度的4.2倍,积分闪烁效率达到BGO晶体的55.6%,这有利于在高分辨率医学成像中降低辐射剂量。 相似文献
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Radio-, photo- and thermo-luminescence were measured for two sets of PbWO 4 single crystal samples doubly doped with Mo and Nb 5+ /Ta 5+ ions. Pentavalent ion codoping of PbWO 4 :Mo enhances the radioluminescence intensity to the level exceeding that of BGO scintillator. However, it introduces a new trapping level, which is reflected by the intense thermoluminescence-glow-curve peak around 100 v K. This trapping center is probably responsible for the increased occurrence of slow decay components in such doubly doped PbWO 4 . 相似文献
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I. Stefaniuk 《Opto-Electronics Review》2018,26(2):81-91
In this topic review the results of the X-band electron paramagnetic resonance (EPR) measurements of Mn, Co, Cr, Fe ions in YAlO3 (YAP) crystals and Fe ions in LiNbO3 (LNO) crystals and of chromium doped Bi12GeO20 (BGO) and Ca4GdO(BO3)3 single crystals, are presented. It is well known that the oxide crystals (for example:YAP, LNO, BGO) are one of the most widely used host materials for different optoelectronic applications. The nature of point defect of impurities and produced in the oxide crystal after irradiation by bismuth ions and after irradiation by the 235U ions with energy 9.47 MeV/u and fluency 5?×?1011?cm?1 is discussed. The latter is important for applications of these oxide crystal as laser materials. 相似文献
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It is reported that the dependence of BGO light output on treatment of the surfaces of BGO crystal has been tested. The results indicate that the light output of BGO is larger when the coupling surface of BGO is more roughenned, and the other five surfaces are optically polished and wrapped with white paper. 相似文献
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H^+注入锗酸铋(Bi4Ge3O12或BGO)晶体引起某些效应,如辐射损伤,光学吸收和近表层区域的晶体分解。经H^+注入后,BGO晶体的颜色变成棕色,但实验中证实不了该变化是由色心的产生所引起。此外,实验中也示观察到H^+注入BGO晶体中有离子束诱发的光学活性变化。可见在注入过程中,未发生从Bi4Ge3O12转变到Bi12GeO20的结构相变,由此预见,注入过程中可能发生离子束引起的晶体分解。H^ 相似文献
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Yi-Ming Hu Jin Chang Deng-Yi Chen Jian-Hua Guo Yun-Long Zhang Chang-Qing Feng 《中国物理C(英文版)》2016,40(11):116003-116003
DArk Matter Particle Explorer (DAMPE) is the first Chinese astronomical satellite, successfully launched on Dec. 17 2015. As the most important payload of DAMPE, the BGO calorimeter contains 308 bismuth germanate crystals, with 616 photomultiplier tubes, one coupled to each end of every crystal. Environmental tests have been carried out to explore the environmental adaptability of the flight model of the BGO calorimeter. In this work we report the results of the vibration tests. During the vibration tests, no visible damage occurred in the mechanical assembly. After random or sinusoidal vibrations, the change of the first order natural frequency of BGO calorimeter during the modal surveys is less than 5%. The shift ratio of Most Probable Value of MIPs changes in cosmic-ray tests are shown, the mean value of which is about -4%. The comparison of results of cosmic-ray tests before and after the vibration shows no significant change in the performance of the BGO calorimeter. All these results suggest that the calorimeter and its structure have passed through the environment tests successfully. 相似文献
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Self-Q-switched diode-end-pumped Nd:BGO laser¥HUWentao;ZHOUFuzheng;FANDianyuan;JIANGZhonghong(ShanghaiinstitufeofOpticsandFin... 相似文献
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研究了BGO晶体在不同温度下(在300—1323 K的温度范围)的拉曼光谱及其熔体的高温拉曼光谱,分析了BGO晶体结构随温度变化的规律及BGO熔体的结构特征.随着温度的升高,BGO晶体的拉曼光谱谱峰都不同程度地向低波数方向移动,也存在不同程度的展宽,同时强度减弱.另外,在BGO熔体中存在[GeO4]和[BiO6]的结构基团;但两种结构之间的联键消失,即在熔体中二者是相互独立的生长基元.
关键词:
高温拉曼光谱
熔体
BGO晶体 相似文献
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We demonstrate the fabrication of symmetric waveguides in a bismuth germanate (BGO) single crystal using a double line approach by an 80Ohm [emtosecond laser. The optical attenuation of the single mode waveguide is measured to be 4.2 dB/cm at 633nm. The influence of pulse energy and focal depth on the end facet of the irradiated region is also studied. This technique is promising to fabricate buried BGO waveguide arrays used in positron emission tomography systems. 相似文献
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Trivalent bismuth luminescence is reported in three Sillen bismuth oxyhalide phases, SrBiO2Cl, BaBiO2Cl, and BaBiO2Br. These compounds exhibit Bi 6s6p→6s2 emission under UV and X-ray radiations. At room temperature, BaBiO2Cl shows the most intense light emission, with spectral and decay properties similar to those found in Bi4Ge3O12 (BGO). At low temperatures, each phase show an increase in the photoluminescence intensities and a narrowing of the emission peaks. In contrast to the temperature dependence of BGO, X-ray excited luminescence intensities of all three phases remain relatively constant throughout the temperature range 10-295 K, though much lower than BGO at low temperatures. This result indicates that the Sillen phases undergo less thermal quenching than BGO. The low temperature and room temperature radio-luminescence decay times were determined from pulsed X-ray measurements. At room temperature, SrBiO2Cl exhibits faster decays than BGO, while BaBiO2Cl and BaBiO2Br have decay times similar to BGO. 相似文献
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T. I. Milenov V. I. Dimov P. M. Rafailov M. M. Gospodinov 《Applied Physics A: Materials Science & Processing》2008,92(3):643-649
Lattice defects in a scintillation detector made of Bi4Ge3O12 (BGO) could severely impact detector efficiency via non-radiative transfer of electron excitation, thus making thorough investigations
of these defects highly important. Here we present a combined experimental and theoretical study of two- and three-dimensional
defects in a Czochralski-grown BGO crystal. Upon examination by transmission electron microscopy the selected-area electron
diffraction (SAED) patterns in two neighboring parts of the specimen reveal different kinds of two- and three-dimensional
defects. Three sub-grains misoriented at 2.47° with reference to each other and probable presence of stacking faults lying
in {011} planes were observed in the first examined local area. The SAED image taken from an area in the close neighborhood
is much more complicated and is explained in terms of the superposition of reflections from: (i) a partially textured GeO2 second-phase inclusion; (ii) the basic lattice of BGO and (iii) a superlattice-like structure based on the BGO lattice. The
atomic structure of such a superlattice-like structure was theoretically modeled and the corresponding simulated SAED patterns
were found to be in good agreement with the experimentally observed one. 相似文献
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首次实现了LK泵浦Nd∶BGO固体激光器的1.064μm的激光输出,泵浦阈值功率为25mW,在连续运转状态下得到最大为40mW的TEM00模输出,光-光效率为13.3%,根据法拉第磁光效庆理论,了LD泵浦Nd∶BGO自调Q激光器的各种参数,并研制成该激光器,在该器件中,作为损耗调制元件的磁光调制器就是绕有线圈的Nd∶BGO晶体本身,实验在重复率为1KHz的条件下得到了FWHM为100ns的稳定脉冲 相似文献