Optical Property of LiNbO3 Crystal Codoped with In, Mg and Fe

In2O3, MgO and Fe2O3 were doped in LiNbO3 and Czochralski method was used to grow In:Mg:Fe:LiNbO3 crystals. The OH- extension transmission spectra, light scattering resistance ability, two wave coupled diffraction efficiency and response time of the crystal were measured. Codoping In and Mg in crystal will improve its light scattering resistance ability and response time. Doping In can increase the ability to replace antisite Nb and decrease the doping quantity of Mg. All these are propitious to improve the optical homogeneity of crystal. Doping Fe can improve the photorefractive sensitivity for LiNbO3 crystal. We discussed the site of In, Mg and Fe in LiNbO3 crystals and the influence of the absorption peak of OH- transmission spectra on photorefractive property for LiNbO3 crystal.     

Investigation of Mechanism of Co-doped Zn2+ and In3+ Influence on Optical Properties of Fe∶LiNbO3

Doping Zn with the concentration of 3mol% and In2O3 with different concentrations in Fe∶LiNbO3, Zn∶In∶Fe∶LiNbO3 crystals were grown.　The infrared spectra of the crystals were measured and the mechanism of the OH-, absorption peak shifting was studied. The diffraction efficiency, response time and photoconduction of the crystals were measured. The mechanisms of the photoconduction increasing, diffraction efficiency decreasing and response time shorting for those crystals were studied.     

双掺杂LiNbO_3晶体光谱和光折变特性

报道了双掺杂Ce :Fe ,Ce :Mn ,Mn :Fe生长态LiNbO3(LN)的光谱及光折变效应二波耦合增益特性 .研究表明 ,双掺杂浓度较高时 ,生长态的LiNbO3晶体的透过率光谱范围较小 ,光折变效应二波耦合增益较低 .几种双掺杂晶体都比单掺Fe晶体的光折变效应二波耦合增益低 ,表现出较强的抗光折变特性     

The Effect of Oxidation／Reduction Disposing on Optical Properties of Mg： Fe： Mn： LiNbO3 Crystals

The congruent tri-doped Mg: Mn: Fe: LiNbO3 crystal has been grown by Czochralski method. Some crystal samples are reduced in Li2CO3 powder at 500℃ for 24 hours or oxidized for 10 hours at 1100 ℃ in Nb2O5 powder. Compared with As-grown Mg:Mn:Fe:LiNbO3, the absorption edge in UV-Vis. absorption spectrum of the oxidized sample and the reduced shifts to the violet and the red, respectively. Reduction increases the absorption of crystals in visible light region. In two-wave coupling experiments, the writing time, maximum diffraction efficiency and the erasure time of crystal samples in the same conditions are determined. The results indicate that oxidation and reduction disposing has great effect on the holographic recording properties of these crystals. The reduced crystal exhibits the fastest response time of 160 s anmng the crystal series. The mechanism of post-disposing effect on the holographic recording properties of Mg:Mn:Fe:LiNbO3 crystals are investigated.     

LiNboO_3:Fe晶体中入射光光强分布对“扇形”光的影响

研究了LiNbO3：Fe晶体中入射光光强分布对“扇形”光的影响．结果证明,其影响很小．由此,可得出结论,LiNbO3：re晶体中的“扇形”光的种子光来源于晶体中的缺陷散射．     

Growth and Holographic Storage Properties of Fe:LiTaO3 Crystal

Using Si-Mo bar as heater and doping Fe2O3 in LiTaO3, Fe∶LiTaO3 crystal was grown by Czochralski method. The curie temperature of the crystal was measured by thermal analyze method. The lattice constants of the crystal were calculated by measuring of X-ray spectra. The response time, exponential gain coefficient and diffraction efficiency of Fe:LiTaO3 were obtained by two wave coupled technique. Compared with Fe∶LiNbO3, the response time of Fe:LiTaO3 is six times shorter, the storage time of Fe:LiTaO3 is ten times longer and the photo scattering resistance ability of Fe:LiTaO3 is four times higher. Fe:LiTaO3 is an excellent holographic storage material.     

Studies of Photorefractive Crystals of Double-Doped Ce,Fe:LiNbO3

In this paper, photorefractive crystals of Ce, Fe:LiNbO3 are systematically studied. The crystals have been grown by Czochralski method. The samples with different doping concentrations and oxidation/reduction treatments have been fabricated. Their photorefractive properties were experimentally investigated by using two-beam coupling. The results show that the photorefractive efficiency depends on the dopant concentration, oxidation/reduction treatment, and light wavelength. The doping mechanism is also discussed here.     

Studies of Photorefractive Crystals of Double-Doped Ce,Fe:LiNbO3

In this paper, photorefractive crystals of Ce, Fe:LiNbO3 are systematically studied. The crystals have been grown by Czochralski method. The samples with different doping concentrations and oxidation/reduction treatments have been fabricated. Their photorefractive properties were experimentally investigated by using two-beam coupling. The results show that the photorefractive efficiency depends on the dopant concentration, oxidation/reduction treatment, and light wavelength. The doping mechanism is also discussed here.     

Bleaching effect and nonvolatile holographic storage in doubly doped LiNbO<Subscript>3</Subscript>:Fe:Cu crystals

The bleaching effect, i. e. the crystal shows that decoloration after it is illuminated by ultraviolet light, has been observed in congruent LiNbO3:Fe :Cu crystals. Based on this bleaching effect, a new technique including the reco rding phase by two interfering red beams and fixing phase by both UV light and a coherent red beam has been experimentally investigated to realize nonvolatile holographic storage in LiNbO3:Fe:Cu. The results of proof-of-concept experiments confirm that bleaching effect becomes an alternative physical mechanism for nonv olatile holographic storage with high recording sensitivity and weak light-induced scattering noise.     

In掺杂对Er:LiNbO3晶体上转换荧光性能的影响

采用Czochralski方法生长了同成分Er(1%):LiNbO3和In(2%):Er(1%):LiNbO3晶体(摩尔分数)。采用红外透射光谱来研究晶体样品的缺陷结构,研究发现,随着In3+离子的掺入,Er:LiNbO3晶体的OH吸收峰发生紫移,由3481cm-1移至3 508 cm-1。以飞秒激光为激发光源测试了晶体样品的上转换荧光光谱,发现In:Er:LiNbO3晶体中Er3+离子的发光强度有明显提高。结合紫外-可见吸收光谱和上转换光谱,分析了In:Er:LiNbO3晶体中In3+的掺入使Er:LiNbO3上转换发光强度增强的原因,这些结果表明In:Er:LiNbO3晶体用作激光器的增益介质有助于进一步改善激光器性能。     

双掺杂LiNbO3晶体光折变效应图像存储特性

研究了系列双掺杂(Ce：Fe，Mn：Fe，Ce：Mn)以及不同后处理态(生长态、还原态和氧化态)铌酸锂晶体的透过率光谱和光折变全息存储特性．实验结果表明高掺杂铌酸锂样品的透过率光谱范围较窄；氧化态样品具有较大的透过率光谱范围；还原态样品具有较大的光折变二波耦合增益特性．难于同时获得大的波耦合增益和图像存储质量．     

Fe:LiNbO3晶体角度复用全息实验研究

研究了以掺铁铌酸锂(Fe∶LiNbO_3)晶体为记录介质的光折变体的全息记录和读出特性.搭建了角度复用光折变体全息记录的实验光路,记录了光折变全息图.实验研究了Fe∶LiNbO_3晶体的响应灵敏度,测量了光折变体全息记录和读出的衍射效率,测量了最小角度复用间隔,实验结果有助于评估和优化角度复用全息图的容量.     

用铁电晶体四波混频的实时光学检测

对利用铁电晶体掺铁铌酸锂(LiNbO_3:Fe)作记录介质的简并四波混频干涉计量术进行了讨论,提出一种实时测量透明物体的折射率及面形分布不均匀性的实验原理及方法,分析了掺铁铌酸锂晶体在测量中的记录特性,并给出了测量平板玻璃样品的试验结果。     

掺锌铌酸锂（LiNbO3：Zn）晶体的物性测量

本文配制了系列掺锌铌酸锂多晶料，测量了掺锌铌酸锂的熔化温度及居里温度随掺锌量的变化。用熔融提拉法生长了不同掺锌量的铌酸锂单晶。研究了锌在晶体中的分凝、晶体的抗光折变能力和倍频转换效率。实验结果表明：（１）在铌酸锂晶体中，随掺锌量的增加，ＬｉＮｂＯ３：Ｚｎ的熔化温度呈下降趋势，而居里温度线性上升。（２）在掺锌铌酸锂晶体中，调节锌的掺杂量，可以找到分凝系数近于１的掺锌浓度。（３）当掺锌量大于７ｍｏ１％时，ＬｉＮｂＯ３：Ｚｎ晶体与ＬｉＮｂＯ３：Ｍｇ具有同样的抗光折变能力，前者的倍频转换效率比后者稍大。     

大直径掺钕铌酸锂晶体生长及其光学性能研究

在LiNbO3多晶料中依次掺入0.2mol%,0.5mol%和1.0mol%的钕,采用我们自主开发的计算机控制直拉法生长大直径Nd:LiNbO3晶体,测试了晶体的紫外-可见吸收光谱、荧光光谱和红外吸收光谱。由紫外-可见吸收光谱确定泵浦光波长,由荧光光谱确定激光振荡波长;采用X射线荧光光谱分析法测量了Nd:LiNbO3晶体中钕的有效分凝系数,结果是Nd:LiNbO3晶体中钕的有效分凝系数随着钕掺杂浓度的增加而减小。     

铌酸锂的晶体结构

铌酸锂拥有光学、铁电、电光、弹性、弹光、光折射等优良性质,它被广泛应用于集成光和光波导器件.结构决定性质,为此,本文较详细地介绍有关铌酸锂的晶体结构知识.     

Electrochromic effect in domain-inversion process in LiNbO3： Ru： Fe crystals

A reversible electrochromic effect accompanying domain-inversion during the electrical poling process in LiNbO3： Ru： Fe crystals at room temperature has been observed. In electrode area, both electrochromism and domain-inversion occur alternately, and electrochromism is also reversible during back-switch poling, which is experimentally verified and whose mechanism is briefly explained using a microstrncture ferroelectric model. In addition, because of the enhancing elcctrochromic effect, different from the undoped LiNbO3 crystals, the coercive filed （21.0 kV/mm or so） measured in LiNbO3： Ru： Fe is lower than its breakdown field, thus providing a possible new technique for realizing the domain-inversion by constant electric field rather than a pulsed one.     

Structure and properties of Li-rich Zn-doped LiNbO3 Crystal

The Li-rich Zn-doped LiNbO3 (LN) crystals were grown by the Czochralski method. The structure of the crystals was measured by ultraviolet-visible absorption spectra. The results indicated that the Li-rich Zn-doped LN crystals had the same characteristics as the pure LN crystal. After Zn2+ entered into the lattice of Li-rich Zn-doped LN crystal, it replaced NbLi firstly. When there was no NbLi, Zn2+ replaced Li+ then. The second harmonic generation (SHG) property of Li-rich Zn-doped LiNbO3 crystal was measured. The results showed that the SHG conversation efficiency of Li-rich Zn-doped LiNbO3 crystals was higher than that of Zn-doped LiNbO3 crystals.     

晶体不均匀性的“魔镜”诊断方法

“魔镜”检测方法已被有效地应用于镜状表面缺陷的检测，在本文中，我们基于“局域波面畸变”概念，发展了晶体的“魔镜”检测原理，并提出了两种分别用于晶体表面及内部缺陷的无损检测方法。     

有机锡配合物Ph3Sn(OOCC6H4NCHC6H4OH-2)的合成及晶体结构

利用Ph3SnCl与N-亚水杨酰基-4-氨基苯甲酸以1∶1摩尔比反应,合成了Ph3Sn(OOCC6H4NCHC6H4OH-2).用X-射线单晶衍射测定了该配合物的晶体结构,结果表明,在该配合物的晶体中,锡原子呈五配位畸变三角双锥构型.