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1.
Xiudong Sun Hongxin Shi Suhua Luo Yongyuan Jiang Qingxin Meng 《Crystal Research and Technology》2010,45(3):249-253
Hf:Fe:LiNbO3 crystals were grown in air by the Czochralski technique with various ratios of [Li]/[Nb]=0.94, 1.05, 1.20 in melt. The defect structure and location of doped ions were analyzed by the UV‐visible and infrared spectroscopy. The optical damage resistance ability of Hf:Fe:LiNbO3 crystals was measured by the photo‐induced birefringence change and the transmitted light spot distortion method. The results show that the optical damage resistance ability of Hf:Fe:LiNbO3 crystals is enhanced with the increase of the [Li]/[Nb] ratio. The dependence of the optical damage resistance of Hf:Fe:LiNbO3 crystals on the defect structure is discussed in detail. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
2.
Influence of defect structure on the infrared transmission spectra of OH‐ in Zn:Fe:LiNbO3 crystals with various ZnO concentration and different Li/Nb ratios was investigated. It indicates that above the Zn concentration threshold the OH‐ absorptions bands successively shift from 3482cm‐1 to 3504cm‐1 and 3529cm‐1. The intensity of the 3504cm‐1 band increases with ZnO concentration increasing. The optical damage resistance of the Zn:Fe:LiNbO3 crystals increases rapidly when the ZnO concentration exceeds a threshold value. This result contributed to the site alteration from the Li sites to Nb sites due to Zn‐doping in crystal. © 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim 相似文献
3.
A series of Sc:Er:LiNbO3 crystals have been grown by Czochralski method. Their ultraviolet‐visible (UV‐Vis) absorption spectra was measured and discussed to investigate their defect structure. The optical damage resistance of Sc:Er:LiNbO3 crystals was characterized by the transmitted beam pattern distortion method. It increases remarkably when the concentration of Sc2O3 exceeds a threshold concentration. The optical damage resistance of Sc (3.0mol %):Er:LiNbO3 is much higher than that of the Er:LiNbO3. The intrinsic and extrinsic defects were discussed to explain the enhance of the optical damage resistance in the Sc:Er:LiNbO3 crystals. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
4.
Hongxin Shi Changyu Ren Suhua Luo Qingxin Meng Xiudong Sun 《Crystal Research and Technology》2011,46(9):931-934
Hf:Fe:LiNbO3 crystals were grown in air by the Czochralski technique with various [Li]/[Nb] ratios ([Li]/[Nb]=0.94, 1.05, 1.20) in melt. The defect structure and location of doped ions were analyzed by the UV‐visible absorption spectra. The optical damage resistance of Hf:Fe:LiNbO3 crystals was investigated by the photoinduced birefringence change and the transmitted light spot distortion method. The results show that the optical damage resistance ability of Hf:Fe:LiNbO3 crystals decreases with the increase of the [Li]/[Nb] ratio. The dependence of the optical damage resistance of Hf:Fe:LiNbO3 crystals on the defect structure is discussed in detail. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
5.
In:Fe:Cu:LiNbO3 crystals were grown in air by the Czochralski technique with various [Li]/[Nb] ratios of 0.946, 1.050, 1.200, and 1.380 in melt. Based on the ICP‐AES (inductively coupled plasma atomic emission spectrometry) analyzed results, the chemical formula of the triple‐doped In:Fe:Cu:LiNbO3 crystals were obtained. It can be seen that the near‐stoichiometric ratio value is between 1.050 and 1.200 for our samples. The optical damage resistance of In:Fe:Cu:LiNbO3 crystals was characterized by changes in light‐induced birefringence and it increases with the increasing of [Li]/[Nb] ratios. The dependence of the optical damage resistance on the defect structure of In:Fe:Cu:LiNbO3 crystals is discussed in detail based on the obtained chemical formulas. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
6.
A series of In:Nd:LiNbO3 crystals were grown by Czochralski technique and were made into waveguide substrates. The optical damage resistance of the In:Nd:LiNbO3 waveguide substrates was characterized by measurement of the holographic method. The optical damage resistance of In (3.0 mol%):Nd:LiNbO3 was much higher than that of other In:Nd:LiNbO3. The ultraviolet‐visible (UV‐Vis) absorption spectra the In:Nd:LiNbO3 crystals were measured and investigated. The structure defects were discussed in this paper to explain the enhance of the optical damage resistance in the In:Nd:LiNbO3 crystals. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
7.
Zn:Mn:Fe:LiNbO3 crystals were prepared by Czochralski technique. Its microstructure was measured and analyzed by UV‐Vis absorption spectra. The optical damage resistance of Zn:Mn:Fe:LiNbO3 crystals was characterized by the transmitted beam pattern distortion method. It increases remarkably when the concentration of ZnO is over a threshold concentration. Its value in Zn(7.0 mol%):Mn:Fe:LiNbO3 crystal is about three orders of magnitude higher that in the Mn:Fe:LiNbO3 crystal. The dependence of the defects on the optical damage resistance was discussed. The non‐volatile holographic storage was realized in all crystals, and the sensitivity of the Zn(7.0 mol%):Mn:Fe:LiNbO3 crystal is much higher than that of others. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
8.
A series of In:Yb:Er:LiNbO3 crystals have been grown. The UV‐Vis absorption spectra and Infrared (IR) transmission spectra were measured and discussed in terms of the spectroscopic characterizations and the defect structure of the In:Yb:Er:LiNbO3 crystals. The optical damage resistance was characterized by the transmitted beam pattern distortion method. The optical damage resistance of In (3.0mol %):Yb:Er:LiNbO3 crystal is one order of magnitude higher than that of other crystal. The dependence of the optical damage resistance on the defect structure was studied. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
9.
10.
Chao Xu Zhaopeng Xu Yexia Fan Lei Xu Chunhui Yang Yuheng Xu 《Crystal Research and Technology》2012,47(8):863-867
Mg:Ru:Fe:LiNbO3 crystals with various doping concentration of MgO have been grown by Czochralski method. The type of charge carriers and photorefractive properties in Mg:Ru:Fe:LiNbO3 crystals were measured by two‐wave coupling method using Kr+ laser (476 nm) and He‐Ne laser (633 nm) as light sources. We found that holes were the dominant charge carriers under blue light irradiation while electrons were the dominant charge carriers under red light irradiation. Mg2+ ions behaved no longer as damage resistant, but promoter to the photorefractive properties at 476 nm wavelength. The photorefractive properties under blue light improved with the increase concentration of Mg2+ ions. The enhancement mechanisms of the blue photorefractive were suggested. Experimental results definitely showed that Mg‐doped two‐centre Ru:Fe:LiNbO3 was a promising blue photorefraction material for holographic volume storage. 相似文献
11.
Yannan Qian Rui Wang Lili Xing Yanling Xu Chunhui Yang Xinrong Liu 《Crystal Research and Technology》2011,46(11):1137-1142
Congruent Er3+(3 mol%):LiNbO3 crystals codoped with ZnO (X mol %, X=0, 3, 6 and 7) were grown by the Czochralski technique. The Er contents in the crystals were measured by an inductively coupled plasma atomic emission spectrometer (ICP‐AES). Under 800 nm excitation, the upconversion emission spectra reveal an enhancement of the green emission with respect to the red emission when the Zn2+ ions are introduced into Er:LiNbO3 crystal. The effect of Zn2+ ions concentration on the intensity ratio of the green to red emission has been investigated. Two cross‐relaxation processes (2H11/2 + 4I13/2 → 4I11/2 + 4F9/2 and 4F7/2 + 4I11/2 → 4F9/2 + 4F9/2) are involved in populating the 4F9/2 state, which bypass the green‐emitting states. The OH‐ absorption spectra indicate that the Zn2+ codoping leads to a decreased concentration of Er3+ cluster sites contributing to the enhancement of the green emission. The studies on UV‐vis absorption spectra show that the heavily codoped with Zn2+ results in the reformation of the Er3+ cluster sites in Er:LiNbO3. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
12.
Chao Xu Chunhui Yang Yang Mo Yijie Wang Liang Sun Liangcai Cao Yuheng Xu 《Crystal Research and Technology》2010,45(11):1123-1126
Near‐stoichiometric LiNbO3 single crystal tri‐doped with ZrO2, MnO and Fe2O3 was grown from Li‐riched melt by Czochralski method. The defect structures and composition of these crystals were analyzed by means of ultraviolet‐visible and infrared transmittance spectra. The appearance of 3466 cm‐1 peak in infrared spectra showed that the crystal grown from Li‐riched melt was near stoichiometric. The photorefractive properties at the wavelength of 488 nm and 633 nm were investigated with two‐beam coupling experiment, respectively. The experimental results showed that the response speed and sensitivity were enhanced significantly and the high diffraction efficiency was obtained at 488 nm wavelength. This manifested that near‐stoichiometric LiNbO3:Mn:Fe:Zr crystal was an excellent candidate for holographic storage. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
13.
In this paper, photorefractive properties of Mg:Ce:Cu:LiNbO3 crystals were studied. The crystals doped with different concentration of Mg ions have been grown by the Czochralski method. Mg concentrations in grown crystals were analyzed by an inductively coupled plasma optical emission spectrometry (ICP‐OE/MS). The crystal structures were analyzed by the X‐ray powder diffraction (XRD), ultraviolet‐visible (UV‐Vis) absorption spectra and infrared (IR) transmitatance spectra. The photorefractive properties of crystals were experimentally studied by using two‐beam coupling. In this experiment we determined the writing time, maximum diffraction efficiency and the erasure time of crystals samples with He‐Ne laser. The results showed that the dynamic range (M/#), sensitivity (S) and diffraction efficiency (η) were dependent on the Mg doping concentration, and the Mg(4.58mol%):Ce:Cu:LiNbO3 crystal was the most proper holographic recording media material among the six crystals studied in the paper. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
14.
Li Dai Yanqing Su Shiping Wu Jingjie Guo Zizhi Li Yuheng Xu 《Crystal Research and Technology》2009,44(7):754-758
A series of Zn:In:Fe:LiNbO3 crystals were prepared by Czochralski method. The crystal composition and defect structure were analyzed by ICP‐OE/MS, UV–vis and IR spectroscopy. The results show that with increasing In3+ doping concentration in melt, the segregation coefficients of both Zn and In ions decrease. The optical damage resistance of Zn:In:Fe:LiNbO3 crystals was studied by the transmitted beam pattern distortion method. It is found that the optical damage resistance of Zn:In(3mol%):Fe LiNbO3 crystals is two orders of magnitude higher than that of Zn:Fe:LiNbO3. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
15.
Liang Sun Chun‐Hui Yang Yu‐Heng Xu Lian‐Cheng Zhao 《Crystal Research and Technology》2009,44(4):433-439
Codoped Hf: Er: LiNbO3 crystals have been grown by the Czochralski technique. Defect structures of the crystals were analyzed by IR absorption spectra, and the compositions of the crystals were measured by X‐ray fluorescent spectrograph. A new OH–‐associated vibrational peak at 3492 cm–1 was revealed in 6 mol % Hf: 1 mol % Er: LiNbO3 crystal. It was attributed to (HfNb)–‐OH–‐(ErNb)2– defect centers. The Er3+ concentrations in crystals gradually decreased with the increase of the codoped Hf4+ concentrations in the melts. The emission characteristics of the crystals were investigated by the fluorescence spectrum. It was found that the luminescent intensity in codoped 6 mol % Hf: 1 mol % Er: LiNbO3 crystal was 3.5 times stronger than that in single doped 1 mol % Er: LiNbO3 crystal. The luminescent enhancement effect was successfully explained on the basis of defect structure of the crystals. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
16.
Liang Sun Haitao Yu Qiang Lv Fengyun Guo Hongtao Li Wei Cai Yuheng Xu Liancheng Zhao 《Crystal Research and Technology》2007,42(7):730-736
Mg: Er: LiNbO3 crystals were grown by the Czochralski technique with various concentrations of MgO = 2 mol%, 4 mol%, 6 mol% and the fixed concentration of Er2O3= 1 mol% in the melt, and the 8 mol%Mg: 1 mol%Er: LiNbO3 crystal was fabricated by the Czochralski technique with special technology process. The crystals were treated by polarization, reduction and oxidation. The segregation coefficients of Mg2+ and Er3+ in Mg: Er: LiNbO3 crystals were measured by X‐ray fluorescence spectrograph, as well as the crystal's defect structure and optical properties were analyzed by the UV‐Vis, IR and fluorescent spectroscopy. The pump wavelength and the surge wavelength were determined. Using m‐line method tested optical damage resistance of those crystals, the results show that photodamage threshold of Mg: Er: LiNbO3 crystals are higher than that of Er: LiNbO3 crystal, and the oxidation treat could enhance the photodamage resistant ability of crystals while the reduction treat could depress the ability. The optical damage resistance of 8 mol%Mg: 1 mol%Er: LiNbO3 crystal was the strongest among the samples, which was two orders magnitude higher than that of 1 mol%Er: LiNbO3 crystal. The dependence of the optical properties on defect structure of Mg: Er: LiNbO3 crystals was discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
17.
In:Zn:LiNbO3 crystals doped with different indium concentrations were grown by Czochralski technique. The optical damage threshold value and ultraviolet‐visible absorption spectra of the In:Zn:LiNbO3 crystals were measured. The In:Zn:LiNbO3 crystals were made into optical waveguide substrates using hexanedioic acid as proton exchange agent. The optical damage resistant ability of those optical waveguide substrates was investigated by the m‐line method. The optical damage threshold values of In(2mol.%):Zn(3mol.%):LiNbO3 crystal and optical waveguide substrate are two orders of magnitude higher than those of pure LiNbO3. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
18.
Shuangquan Fang Zhaoxiang Han Yingjie Qiao Yingying Liu Qi Jia 《Crystal Research and Technology》2009,44(11):1211-1214
With K2O as flux, near‐stoichiometric In:LiNbO3 (In:SLN) crystals with different indium contents were grown by the top seed solution growth (TSSG) method. Defect structure characteristics and the replacement principle of extrinsic ions were derived from X‐ray powder diffraction, differential thermal analysis (DTA), ultraviolet‐visible (UV) absorption and infrared (IR) spectrum measurement. Further analysis indicated that the threshold concentration of In2O3 in near‐stoichiometric LiNbO3 crystals were about 1.1 mol%. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
19.
在铌酸锂(LiNbO3,LN)中掺入摩尔分数为0.1;的CeO2,以提拉法从不同[Li]/[Nb]摩尔比([Li]/[Nb]=0.750,0.850,0.946,1.100)的熔体中生长出了Ce:LN晶体.测试了晶体的晶格常数、红外光谱和居里温度.结果表明:随着[Li]/[Nb]比的增加,晶体仍为三方的LN晶体,且晶格常数和晶胞体积没有发生大的变化,v(OH-)振动峰的位置依次向长波方向移动,居里温度依次增加,结构缺陷减少.由于Ce和[Li]/[Nb]比的协同作用,[Li]/[Nb]比为1.100的Ce:LN晶体已接近化学计量比,[Li]/[Nb]比为0.850的Ce:LN晶体的居里温度近似等于纯LN晶体.利用二波耦合光路测试了晶体的衍射效率、写入时间和擦除时间,计算了晶体的光折变灵敏度及动态范围.测试了晶体的抗光致散射能力,结果表明:[Li]/[Nb]比越高的Ce:LN晶体的光折变性能越好.并分析了不同[Li]/[Nb]比Ce:LN晶体光折变性能增强的机理. 相似文献
20.
Liu Bo Li Chunliang Bi Jiancong Sun Liang Xu Yuheng 《Crystal Research and Technology》2008,43(3):260-265
Hf(2mol%):Fe(0.05wt%):LiNbO3 crystals with various [Li]/[Nb] ratios of 0.94, 1.05, 1.2 and 1.38 have been grown. The photorefractive resistant ability increases with the accretion of [Li]/[Nb] ratio. When the ratio of [Li]/[Nb] is 1.20 or 1.38, the OH‐ absorption band shifts to about 3477cm‐1. The mechanisms of the photorefractive resistant ability increase and the absorption band shift have been discussed. The exponential gain coefficient (Γ) of the crystals was measured with two‐beam coupling method and the effective charge carrier concentration (Neff) was calculated. The results show that Γ and Neff increase with the accretion of [Li]/[Nb] ratio. The temperature effect of codoped Hf:Fe:LiNbO3 crystals was also studied, it was found that the exponential gain coefficient increase dramatically at about 55°C, 70°C and 110°C, this is due to the inner electric field which is resulted from structure phase change. (© 2007 WILEY ‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献