24 resultados para THULIUM

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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Structural and up-conversion fluorescence properties in ytterbium-sensitized thulium-doped novel oxychloride bismuth-germanium glass have been studied. The structure of novel bismuth-germanium glass was investigated by peak-deconvolution of Raman spectrum, and the structural information was obtained from the peak wave numbers. The Raman spectrum investigation indicates that PbCl2 plays an important role in the formation of glass network, and has an important influence on the up-conversion luminescence. Intense blue and weak red emissions centered at 477 and 650 mn, corresponding to the transitions 1G(4) -> H-3(6) and (1)G(4) -> H-3(4), respectively, were observed at room temperature. The possible up-conversion mechanisms are discussed and estimated. This novel oxychloride bismuth-germanium glass with low maximum phonon energy (similar to 730 cm(-1)) can be used as potential host material for up-conversion lasers. (c) 2005 Elsevier Ltd. All rights reserved.

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We report a novel phenomenon in GeS2-In2S3-CsI chalcohalide glass doped with Tm3+ ions. Under irradiation with an 808 nm laser diode, a bright red emission centered at 700 nm is observed for the first time in this glass. The log-log correlation between integrated emission intensity and pump power reveals that a two-photon absorption process is involved in the phenomenon, suggesting that the F-3(3,2) -> H-3(6) transition of Tm3+ ions is responsible for the appearance of the red emission. The results indicate that the indium (In) based chalcohalide glass containing Tm3+ ions is expected to find applications in visible lasers, high density optical storage and three-dimensional color displays. (C) 2009 Elsevier B.V. All rights reserved.

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We report on the room-temperature continuous-wave (CW) operation of a Ho:YAlO3 laser that is resonantly end pumped at 1.94 mu m by a diode-pumped thulium-doped laser in the same host. Through the use of a 1 at % Ho3+-doped 20-mm-long YAlO3 crystal (b cut), the Ho:YAlO3 laser generated 1 W of linearly polarized (E//c) output at 2118 nm and 0.55 W of E//a output at 2128.5 nm for an incident pump power of 5 W, with an output coupler transmission of 14 and 3%, respectively. An optical-to-optical conversion efficiency of 20% and a slope efficiency of 33% were achieved at 2118 nm corresponding to an incident pump power.

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A series of ternary Ln(tta)(3)L complexes (Ln = Ho, Tm; Htta = 2-thenoyltrifluoroacetone; L = 1,10-phenanthroline, 2,2'-bipyridine, or triphenyl phosphate oxide) and their corresponding sol-gel hybrid materials formed via the in situ synthesis process (designated as Ln-T-L gel) were reported. The complexes and the gels were studied in detail, which suggest the complexes have been successfully synthesized in the corresponding gels.

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Two beta-diketones 4,4,4-trifluoro-1-2-thenoyl-1,3-butanedione (Htta) and 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (Htfnb), which contain trifluoroalkyl chain, were selected as the main sensitizer for synthesizing Tm(L)(3)phen (L = tta, tfnb) complexes. The two near-infrared (NIR) luminescent thulium complexes have been covalently bonded to the ordered mesoporous material MCM-41 via a functionalized 1,10-phenanthroline (phen) group 5-(N,N-bis-3-(triethoxysilyl)propyl)ureyl-1,10-phenanthroline (phen-Si) [The resultant mesoporous materials are denoted as Tm(L)(3)phen-MCM-41 (L = tta, tfnb)]. The Tm(L)(3)phen-MCM-41 (L = tta, tfnb) mesoporous materials were characterized by small-angle Xray diffraction (XRD) and N-2 adsorption/desorption, and they show characteristic mesoporous structure of MCM-41.

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The crystal structure of a ternary Tm(DBM)(3)phen complex (DBM - dibenzoylmethane; phen = 1. 10-phenanthroline) and the synthesis of hybrid mesoporous material in which the complex covalently bonded to mesoporous MCM-41 are reported. Crystal data: Tm(DBM)(3)phen C59H47N2O7Tm, monoclinic P21/c, a = 19.3216(12) A, b = 10.6691(7) A, c = 23.0165(15)A, alpha = 90, beta = 91.6330(10), gamma = 90, V = 4742.8(5) A(3), Z = 4. The properties of the Tm(DBM)(3)phen complex and the corresponding hybrid mesoporous material [Tm(DBM)(3)phen-MCM-41] have been studied. The results reveal that the Tm(DBM)(3)phen complex is successfully covalently bonded to MCM-41.

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Endohedral metallofullerenes Tm@C-2n were synthesized with the carbon-arc discharge method of activating the Tm2O3-containing graphite anode in situ and back-burning technique, Toluene soxhlet extraction, toluene and pyridine high-temperature and high-pressure extraction technique were employed for the effective extraction of Tm@C-2n. The formation of Tm@C-2n was confirmed by LD-TOF and DEIMS characterization. The mass spectrometric results indicate that Tm@C-2n have a better solubility in toluene and worse solubility in pyridine than other metallofullerenes.

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The laser-atomic-beam spectroscopy technique has been used to make measurements of the hyperfine structure in some odd parity levels of thulium by stepwise excitation. With the experimental results the magnetic dipole hyperfine constants A for the four levels in the configurations 4f12 5d6s6p and 4f12 (H-3(5))6s2 6p3/2 and for two intermediate levels have been obtained.

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The radiative lifetimes of eight excited levels of thulium have been measured with the method of stepwise excitation from the 4f13(F-degrees-7/2)6s2(1S0)\7/2\ ground state to the states studied using two pulsed dye lasers. Optical transients were recorded through observing fluorescences and evaluated with regard to the decay time. The accuracy of the measured lifetime values is about 10%.

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以短的高掺杂浓度的掺铥硅基光纤为增益介质,采用790 nm波长的激光二极管(LD)为抽运源,得到了波长为2 μm的高功率激光输出。当光纤长度为7 cm时,激光器的阈值泵浦功率为135 mW,最大输出功率为1.09 W,斜率效率为9.6%(相对于耦合进光纤的抽运功率)。该激光器的输出稳定性在5%以内。此外,我们还观察分析了工作温度和其他腔结构参量对该激光器工作性能的影响。

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Structural and upconversion fluorescence properties in ytterbium-sensitized thulium-doped oxychloride germanate glass have been studied. The structure of oxychloride germanate glass was investigated by peak-deconvolution of Raman spectrum, and the structural information was obtained from the peak wavenumbers. The Raman spectrum investigation indicates that PbCl2 plays an important role in the formation of glass network, and has an important influence on the upconversion luminescence. Intense blue and weak red emissions centered at 477 and 650 nm, corresponding to the transitions (1)G(4) ->(3) H-6 and (1)G ->H-3(4), respectively, were observed at room temperature. The possible upconversion mechanisms are discussed and estimated. Intense upconversion luminescence indicates that oxychloride germanate glass can be used as potential host material for upconversion lasers. (c) 2004 Elsevier B.V. All rights reserved.