共查询到20条相似文献,搜索用时 46 毫秒
1.
D. K. Mohanty V. K. Rai Y. Dwivedi S. B. Rai 《Applied physics. B, Lasers and optics》2011,104(1):233-236
TeO2–PbO glasses doped/codoped with Er3+/Er3+-Yb3+ ions have been fabricated by melting and quenching method. Efficient frequency upconversion emissions spanning from blue
to red regions corresponding to the 2H11/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions, respectively, upon excitation with 976 nm diode laser radiation have been observed. The variations observed
in the intensity of whole upconversion emission spectra due to the presence of the Yb3+ ions are reported and discussed in detail. 相似文献
2.
3.
This paper reports on the absorption, visible and near-infrared luminescence properties of Nd3+, Er3+, Er3+/2Yb3+, and Tm3+ doped oxyfluoride aluminosilicate glasses. From the measured absorption spectra, Judd-Ofelt (J-O) intensity parameters (Ω2, Ω4 and Ω6) have been calculated for all the studied ions. Decay lifetime curves were measured for the visible emissions of Er3+ (558 nm, green), and Tm3+ (650 and 795 nm), respectively. The near infrared emission spectrum of Nd3+ doped glass has shown full width at half maximum (FWHM) around 45 nm (for the 4F3/2→4I9/2 transition), 45 nm (for the 4F3/2→4I11/2 transition), and 60 nm (for the 4F3/2→4I13/2 transition), respectively, with 800 nm laser diode (LD) excitation. For Er3+, and Er3+/2Yb3+ co-doped glasses, the characteristic near infrared emission bands were spectrally centered at 1532 and 1544 nm, respectively, with 980 nm laser diode excitation, exhibiting full width at half maximum around 50 and 90 nm for the erbium 4I13/2→4I15/2 transition. The measured maximum decay times of 4I13/2→4I15/2 transition (at wavelength 1532 and 1544 nm) are about 5.280 and 5.719 ms for 1Er3+ and 1Er3+/2Yb3+ (mol%) co-doped glasses, respectively. The maximum stimulated emission cross sections for 4I13/2→4I15/2 transition of Er3+ and Er3+/Yb3+ are 10.81×10−21 and 5.723×10-21 cm2. These glasses with better thermal stability, bright visible emissions and broad near-infrared emissions should have potential applications in broadly tunable laser sources, interesting optical luminescent materials and broadband optical amplification at low-loss telecommunication windows. 相似文献
4.
V. Singh V. K. Rai I. Ledoux-Rak L. Badie H.-Y. Kwak 《Applied physics. B, Lasers and optics》2009,97(4):805-809
Alumina (Al2O3) powders doped with Er3+, Yb3+ and Zn2+ ions have been prepared by a low-temperature combustion synthesis technique. The phase purity and crystalline structure of
the combustion products are confirmed by powder X-ray diffraction. An efficient frequency upconversion in the visible region
and the emission in the infrared (IR) region respectively corresponding to the 2H11/2, 4S3/2→4I15/2, 4F9/2→4I15/2 and 4I13/2→4I15/2 transitions upon direct excitation with a CW laser lasing at ∼980 nm are discussed. The enhancement observed in the intensity
of the upconversion emission bands in the visible region and the emission band in the IR region due to the presence of Yb3+ and Zn2+ in Er3+:Al2O3 powders is reported and explained in detail. 相似文献
5.
Deyan Kong Zewei Quan Jun Yang Piaoping Yang Chunxia Li Jun Lin 《Journal of nanoparticle research》2009,11(4):821-829
NaYF4:Yb3+, Er3+ nanoparticles were successfully prepared by a polyol process using diethyleneglycol (DEG) as solvent. After being functionalized
with SiO2–NH2 layer, these NaYF4:Yb3+, Er3+ nanoparticles can conjugate with activated avidin molecules (activated by the oxidation of the oligosaccharide chain). The
as-formed NaYF4:Yb3+, Er3+ nanoparticles, NaYF4:Yb3+, Er3+ nanoparticles functionalized with amino groups, avidin conjugated amino-functionalized NaYF4:Yb3+, Er3+ nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscopy
(AFM), Fourier transform infrared (FT-IR), UV/Vis absorption spectra, and up-conversion luminescence spectra, respectively.
The biofunctionalization of the NaYF4:Yb3+, Er3+ nanoparticles has less effect on their luminescence properties, i.e., they still show the up-conversion emission (from Er3+, with 4S3/2 → 4I15/2 at ~540 nm and 4F9/2 → 4I15/2 at ~653 nm), indicative of the great potential for these NaYF4:Yb3+, Er3+ nanoparticles to be used as fluorescence probes for biological system. 相似文献
6.
7.
V. G. Babajanyan R. B. Kostanyan P. H. Muzhikyan 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2012,47(1):17-22
The results of investigations of luminescent radiations’ kinetic characteristics for LiNbO3:Yb3+-Er3+, LiNbO3:Er3+, and LiNbO3:Yb3+ crystals under optical excitations at 532 nm and 1064 nm wavelengths are presented. The shapes and times of rise and damping
of luminescent signals at 550 nm, 980 nm and 1555 nm wavelengths under selective excitations in the impurity subsystem of
the investigated materials are determined. Comparison of the temporal characteristics of luminescent responses of LiNbO3 crystals doped separately with Yb3+ and Er3+ ions with those of the LiNbO3:Yb3+-Er3+ crystal allows identifying the contributions from different energy transfer processes of optical excitation taking place
in the impurity subsystem of the material. 相似文献
8.
V. Singh V. K. Rai I. Ledoux-Rak H.-Y. Kwak 《Applied physics. B, Lasers and optics》2009,97(1):103-107
The frequency up-conversion, an efficient laser emission and amplification in Er3+:LiAl5O8 phosphors co-doped with Yb3+ and Zn2+ phosphor powders in the 520–560, 640–680 nm regions and at ∼1.5 μm, respectively, have been reported. The emission corresponds
to the 2H11/2, 4S3/2→4I15/2, 4F9/2→4I15/2 and 4I13/2→4I15/2 transitions upon direct excitation into the intermediated 4I11/2 level using ∼980 nm radiation from a CW laser. Possible mechanisms involved for the up-conversion processes based on the
energy level matching scheme, the pump-power dependence and the dynamical behaviour have been discussed. The effect of the
addition of Yb3+ and Zn2+ for the amplification in the 1.5 μm eye-safe telecommunication window has been elaborated and characterized in detail. 相似文献
9.
Infrared-to-visible wave-length conversion in the Yb3+−Er3+ doped phosphors system has been described by a simple three level model based on two ions mechanism. The excitation in the
range of 900–1000 nm of an IR-photon is first absorbed by Yb3+ ion as a sensitizer attributed to the resonant energy transition in Er3+ ion from 4
I
3/2 → 4
S
15/2 and 1
F
9/2 → 4
I
15/2, respectively for green and red emission. The essential energy transfer processes in this system i.e. upconversion from 4
I
11/2 and 1
I
13/2, cross-relaxation from 4
S
3/2 and 1
F
9/2 are taken into account. The limitations of the rate-equation approach are examined with a focus on the underlying dynamics
of this rare-earth system. 相似文献
10.
We report here the luminescence spectra of certain rare earth ions (Eu3+, Tb3+ & Ho3+) doped B2O3-BaO-LiF/AiF3 based on the measurements of emission and decay curves of prominent emission transitions. For both the reference host glasses,
FTIR, XRD, DTA-TG profiles have been recorded to understand their structural and thermal properties. Eu3+ doped glasses have shown five emission transitions of 5D0 → 7F01,2,3 & 4 located at 580nm, 593nm, 615nm, 655nm and 704nm respectively with an excitation at λexci = 392 nm (7F0 → 5L6). Also under an UV source, these europium glasses have displayed a bright red emission from their surfaces. Tb3+ glasses have exhibited four emission bands of 5D4 → 7F6,5,4,3 at 491nm, 547nm, 588nm and 625nm respectively with an excitation at λexci = 376 nm (7F6 → 5G6). Intense green emission from the glass surfaces has been noticed upon exposure to the UV source. Prominently bluish-green emission has been
noticed from the surfaces of the holmium glasses under an UV source and same emission transition (5F4 → 5I8) at 519 nm with an excitation at λexci = 389 nm (5I8 − 5G4) has also been obtained from their measured emission spectra. For all the prominent emissions of the rare earth glasses,
decay curves have been measured to compute their lifetimes. 相似文献
11.
Hyppänen I Hölsä J Kankare J Lastusaari M Pihlgren L Soukka T 《Journal of fluorescence》2008,18(6):1029-1034
The up-converting ZrO2:Yb3+,Er3+ nanomaterials were prepared with the combustion and sol–gel methods. FT-IR spectroscopy was used for analyzing the impurities.
The crystal structures were characterized with X-ray powder diffraction and the mean crystallite sizes were estimated with
the Scherrer formula. Up-conversion luminescence measurements were made at room temperature with IR-laser excitation at 977 nm.
The IR spectra revealed the conventional and OH− impurities for the combustion synthesis products. The structure of the ZrO2:Yb3+, Er3+ nanomaterials was cubic except for the minor monoclinic and tetragonal impurities obtained with the sol–gel method. The materials
showed red (650–700 nm) and green (520–560 nm) up-conversion luminescence due to the 4F9/2→4I15/2 and (2H11/2, 4S3/2)→4I15/2 transitions of Er3+, respectively. The products obtained with the combustion synthesis exhibited the most intense luminescence intensity and
showed considerable afterglow. 相似文献
12.
Vijay Singh Vineet Kumar Rai S. Watanabe T. K. Gundu?Rao Isabelle Ledoux-Rak Ho-Young Kwak 《Applied Physics A: Materials Science & Processing》2010,100(4):1123-1130
YAG phosphor powders doped/codoped with Er3+/(Er3+ + Yb3+) have been synthesised by using the solution combustion method. The effect of direct pumping into the 4I11/2 level under 980 nm excitation of doped/codoped Er3+/Yb3+−Er3+ in Y3Al5O12 (YAG) phosphor responsible for an infrared (IR) emission peaking at ∼1.53 μm corresponding to the 4I13/2→4I15/2 transition has been studied. YAG exhibits three thermally-stimulated luminescence (TSL) peaks at around 140°C, 210°C and
445°C. Electron spin resonance (ESR) studies were carried out to identify the centres responsible for the TSL peaks. The room
temperature ESR spectrum of irradiated phosphor appears to be a superposition of two distinct centres. One of the centres
(centre I) with principal g-value 2.0176 is identified as O− ion, while centre II with an isotropic g-factor 2.0020 is assigned to an F+ centre (singly ionised oxygen vacancy). An additional defect centre is observed during thermal-annealing experiments and
this centre (assigned to F+ centre) seems to originate from an F-centre (oxygen vacancy with two electrons) and these two centres appear to correlate
with the observed high-temperature TSL peak in YAG phosphor. 相似文献
13.
NaYF4:Yb3+, Er3+ nanoparticles were successfully prepared by a polyol process using diethyleneglycol (DEG) as solvent. These NaYF4:Yb3+, Er3+ nanoparticles can be coated with mesoporous silica using nonionic triblock copolymer EO20PO70EO20 (P 123) as structure-directing agent and other materials. The composites can load ibuprofen and release the drug in the phosphate
buffer solution (PBS). The composites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM),
nitrogen absorption/desorption isotherms, fluorescence spectra, and UV/Vis absorption spectra, respectively. The composites
have the mesoporous structure. In addition, the composites emit red fluorescence (from Er3+) under 980 nm near infrared laser excitation, which can be used as fluorescent probes in the drug-delivery system. 相似文献
14.
Vijay Singh R.P.S. Chakradhar Isabelle Ledoux-Rak Laurent Badie Fabienne Pelle Svetlana Ivanova 《Journal of luminescence》2009,129(11):1375-1380
New near-infrared luminescent, monoclinic CaAl2O4:Er3+ phosphor was prepared by using the combustion route at furnace temperatures as low as 500 °C in a few minutes. Combustion synthesized phosphor has been well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive analysis of X-ray (EDAX) mapping studies. The luminescence spectra of Er3+-doped calcium aluminate were studied at UV (380 nm), vis (488 nm) and IR (980 nm) excitation. Upon UV and vis excitation, the CaAl2O4:Er3+ phosphor exhibits emission bands at ~523 nm and at ~547 nm, corresponding to transitions from the 2H11/2 and 4S3/2 erbium levels to the 4I15/2 ground state. A strong luminescence at 1.55 μm in the infrared (IR) region due to 4I13/2→4I15/2 transition has been observed in CaAl2O4:Er3+ phosphor upon 980 nm CW pumping. In the spectrum of IR-excited up-conversion luminescence, green (~523 and ~547 nm) and red (662 nm) luminescence bands were present, the latter associated with the 4F9/2→4I15/2 transitions of Er3+ ions. Both excited state absorption and energy transfer may be proposed as processes responsible for the population of the 4S3/2 and 4F9/2 erbium levels upon IR excitation. The mechanisms responsible for the up-conversion luminescence are discussed. 相似文献
15.
GENERATION OF MULTI-WAVELENGTH VISIBLE LIGHT IN Er3+-DOPED AND Er3+/Yb3+-DOPED SINGLE-MODE OPTICAL FIBER PUMPED AT 1313 nm 下载免费PDF全文
We report the generation of multi-wavelength visible light through amplified spontaneous emission (ASE) in Er3+-doped and Er3+/Yb3+-doped germanosilicate single-mode optical fiber pumped by a Nd:YLF laser at 1313nm. In the Er3+-doped fiber, the intense multi-wavelength blue emission hnes around 463-510nm corre-spond to transitions born 2G7/2 etc. excited states to the metastable 4I13/2 state, and their pumping mechanists is aecomphshed by a stepwise four-photon absorption. Some emission hnes in this wavelength region are attributed to the three-wave sum-frequency process of 1313 and 1530nm (corresponds to 4I13/2 -4I15/2). The intense green emission hnes at 525 and 540 nm are also observed in the Er3+-doped fiber. In the Er3+/Yb3+-doped fiber the blue and green lines are very weak compared with those in the Er3+-doped fiber. 相似文献
16.
V. Singh V. K. Rai S. Watanabe T. K. Gundu?Rao I. Ledoux-Rak H.-Y. Kwak 《Applied physics. B, Lasers and optics》2010,101(3):631-638
The Er3Al5O12 phosphor powders were prepared using the solution combustion method. Formation and homogeneity of the Er3Al5O12 phosphor powders have been verified by X-ray diffraction and energy-dispersive X-ray analysis respectively. The frequency
up-conversion from Er3Al5O12 phosphor powder corresponding to the 2H9/2 → 4I15/2, 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, 4F9/2 → 4I15/2 and the infrared emission (IR) due to the 4I13/2 → 4I15/2 transitions lying at ∼410, ∼524, ∼556, 645–680 nm and at ∼1.53 μm respectively upon excitation with a Ti-Sapphire pulsed/CW
laser have been reported. The mechanism responsible for the frequency up-conversion and IR emission is discussed in detail.
Defect centres induced by radiation were studied using the techniques of thermoluminescence and electron spin resonance. A single
glow peak at 430°C is observed and the thermoluminescence results show the presence of a defect center which decays at high
temperature. Electron spin resonance studies indicate a center characterized by a g-factor equal to 2.0056 and it is observed
that this center is not related to the thermoluminescence peak. A negligibly small concentration of cation and anion vacancies
appears to be present in the phosphor in accordance with the earlier theoretical predictions. 相似文献
17.
通过固相反应法制备了Er3+/Yb3+共掺杂ZrO2-Al2O3粉末的样品,并对样品在980nm激光激发下的上转换发光特性进行了研究.从发射光谱可以发现,在可见光范围内有3个强的发光带,一个位于654nm附近的红光带和两个分别位于545nm、525nm附近的绿光带,分别对应于Er3+离子的以下辐射跃迁:4F9/2→4I15/2、4S3/2→4I15/2、 2H11/2→4I15/2.其中又以Er3+离子的4F9/2→4I15/2跃迁产生的红色荧光辐射最强.对其上转换发光机制进行了分析,发现这三个发光过程都是双光子过程.对样品粉末进行了XRD检测,发现ZrO2主要以立方相为主,并且计算得到了这种立方结构的晶格常数.Al2O3固溶于ZrO2中,Al3+嵌入ZrO2后产生氧空位,导致ZrO2晶体的对称性降低,这种结构变化更有利于提高上转换效率,即上转换发光强度增强.
关键词:
3+/Yb3+')" href="#">Er3+/Yb3+
上转换
2-Al2O3')" href="#">ZrO2-Al2O3
荧光
稀土 相似文献
18.
Bin Dong BaoSheng Cao ZhiQing Feng XingJun Wang ChengRen Li RuiNian Hua 《中国科学G辑(英文版)》2009,52(7):1043-1046
The Er3+-Yb3+ codoped Al2O3 nanoparticles with an average particle size of about 50 nm have been synthesized by an arc discharge synthesis method. The
green and red up-conversion emissions centered at about 526, 547 and 677 nm, corresponding respectively to the 2H11/2→4I15/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3+, were detected by a 978-nm semiconductor laser diode excitation. The Annealing has evident effect on the up-conversion emissions
of the samples: The red up-conversion emission is noticeable before annealing; however, the green up-conversion emission becomes
predominant after annealing. The mixture of (Er,Yb)3Al5O12 and α-(Al,Er,Yb)2O3 phases is more favorable for green up-conversion emissions due to an enhancement of the ESA (I) of 4I11/2+a photon→4F7/2 and ET (III) of 2F5/2(Yb3+)+4I11/2(Er3+)→2F7/2(Yb3+)+4F7/2(Er3+) processes. The two-photon absorption up-conversion process is involved in the green and red up-conversion emissions. The
results have proved that arc discharge synthesis is a new promising preparation technology for optical materials.
Supported by National Natural Science Foundation of China (Grant No. 10804015), the Scientific Research Foundation for Doctor
of Liaoning Province (Grant No. 20071095), and the Educational Committee Foundation of Liaoning Province (Grant No. 2008123) 相似文献
19.
This paper reports the synthesis of high upconversion luminescent Gd2O3: Er3+, Yb3+ nanophosphor through optimized combustion route using urea as a reducing agent. The paper also reports the first observation
of upconversion emission bands extending upto the UV region (335, 366 and 380 nm) in Er3+–Yb3+ co-doped phosphor materials. The fuel to oxidizer ratio has been varied to obtain the maximum upconversion luminescence.
Three high intensity bands are found at 408, 523–548 and 667 nm due to the 4G11/2 → 4I15/2, 2H11/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions, respectively, along with the other bands. Input excitation power dependence has been studied for different transitions,
and the saturation effect and decrease in the slope of different transitions at higher input pump power has been explained.
Heat treatments of the samples show change in crystallite phase/size and relative upconversion luminescence intensities of
blue, green and red bands. The color of the phosphor emission has shown to be tunable with change in the crystal structure
as well as on excitation laser power and Er3+–Yb3+ concentration. The property of color tunability of the phosphor material has been used to record the fingerprint in different
colors. Also, the future prospect of the nanocrystalline phosphor material as a sensor for temperature, using FIR method,
has been explored. 相似文献
20.
Iko Hyppänen Jorma Hölsä Jouko Kankare Mika Lastusaari Marja Malkamäki Laura Pihlgren 《Journal of luminescence》2009,129(12):1739-1743
The effect of the defects due to the charge compensation obtained with the yttrium co-doping to the ZrO2:Yb3+,Er3+ up-converting phosphors was studied. The materials were prepared with the combustion method. The materials purity was analyzed with the FT-IR spectroscopy. The crystal structure was studied with the X-ray powder diffraction and the crystallite sizes were estimated with the Scherrer formula. Up-conversion luminescence was excited at room temperature with an IR-laser at 970 nm. The up-conversion luminescence spectra showed red (650-685 nm) and green emission (520-560 nm) due to the 4F9/2→4I15/2 and (2H11/2,4S3/2)→4I15/2 transitions of Er3+, respectively. Persistent up-conversion luminescence was observed both in the Yb3+,Er3+ and Y3+,Yb3+,Er3+ doped materials. 相似文献