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对铈铁掺杂铌酸锂(Ce:Fe:LiNbO3)晶体进行氧化、还原处理。通过红外光谱、紫外可见吸收光谱测试了晶体样品的组成和缺陷结构。采用透射光斑畸变法测试了晶体样品的抗光损伤能力,结果表明:生长态晶体比还原态晶体的抗光致散射能力基本上高一个数量级,氧化态的晶体要比还原态的晶体高两个数量级。采用二波耦合实验测试了晶体样品的光折变性能,结果表明:从氧化到生长再到还原态,衍射效率逐渐降低,响应时间缩短,光折变灵敏度增加,动态范围逐渐降低。 相似文献
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不同EDTA(乙二胺四乙酸)掺杂浓度条件下生长了KDP(磷酸二氢钾)晶体,超显微法观察了EDTA对KDP晶体光散射性质的影响。结果表明,随着溶液中EDTA含量的增加,相应晶体内部的光散射现象加重。其原因在于当溶液中EDTA含量较高时,阻碍了KDP晶体的生长,导致了液相包裹物的产生,造成光散射;同时发现,同一晶体不同部分的光散射也不同。对EDTA的影响机理进行了初步的探讨。 相似文献
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EDTA对KDP晶体光学性质影响 总被引:2,自引:0,他引:2
本文探讨了不同掺杂浓度下,EDTA对KDP晶体光学性质的影响。结果表明,高浓度EDTA的KDP晶体光散射有明显的影响,但对光学均匀性和光损伤阈值无明显影响。 相似文献
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在生长Fe∶LiNbO3熔体中掺进摩尔分数x(Ru2O3) =0.1%和x(MgO)=1%、3%、7%,用提拉法生长镁钌铁铌酸锂(Mg ∶ Ru∶Fe∶LiNbO3)晶体.通过二波耦合光路,分别以红光(632.8 nm)、绿光(532 nm)和蓝光(476 nm)为光源测量晶体的全息存储性能.实验结果表明,在476 nm下,Mg∶Ru∶Fe∶LiNbO3晶体全息存储性能随着Mg离子掺杂浓度的增加而呈现逐渐增强的趋势,与其在红光和绿光下不同.研究了Mg离子掺杂浓度的增加使Mg∶Ru∶Fe∶LiNbO3晶体的蓝光全息存储性能增强的机理. 相似文献
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一种新型优质光子晶体偏振滤波器的设计 总被引:4,自引:1,他引:3
设计了一种各向异性的一维掺杂光子晶体,利用特征矩阵法研究了该各向异性一维掺杂光子晶体的偏振滤波特性,并与各向同性的一维掺杂光子晶体的两个偏振态缺陷模进行了比较.结果表明,当光以不同角度入射时,透射波中横电波(TE)和横磁波(TM)的缺陷模都会出现明显的分离.利用这个特性设计出一种新型优质光子晶体偏振滤波器. 相似文献
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分析了掺杂铌酸锂晶体的扇形噪声光的形成机制,讨论了信号光与扇形噪声光之间的光放大竞争问题.结果显示:由于信号光与扇形噪声之间光放大竞争,对于信号光的放大而言,存在一个最佳的光生伏特场,因而存在一个最佳入射泵浦光光强,使得信号光具有最大的放大倍数,同时噪声很弱. 相似文献
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JohannWolfsberger M.ElLabban 《红外与毫米波学报》2001,20(1):61-65
分析了普通配置下双波长存储中,不同波长偏离对扇形噪音读出的影响,并从实验上研究了掺铁铌酸锂晶体的最佳读出配置,为能使民存图像完整再现,使用了一个柱面镜来调整读出光的波前,在双掺铌酸锂晶体中实现了整幅图像高信噪比再现,达到了预期效果。 相似文献
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Youbao Wan Junhao Chu Shaoling Guo Lingxian Bo Tianyan Yu Bingkun Yu 《Journal of Infrared, Millimeter and Terahertz Waves》2001,22(1):197-205
The potassium lithium niobate crystals have been grown up. The shapes of solid-melt interfaces which maintaining the steady growth of the potassium lithium niobate crystals have been described. The optical transmission spectrum of the crystal has been surveyed. The perfected crystals showed good Second Harmonic Generation properties. 相似文献
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S. A. Nikitov A. V. Grigor’evskii V. I. Grigor’evskii I. M. Kotelyanskii V. A. Luzanov E. N. Mirgorodskaya S. G. Suchkov 《Journal of Communications Technology and Electronics》2011,56(7):888-899
Two-dimensional phononic crystals are fabricated on the surface of a lithium niobate crystal. A numerical method is developed
for calculating the frequency dependences of the transmission and reflection coefficients of a surface acoustic wave for a
rectangular region with two-dimensional periodic structure on the surface of an elastic body. Measurements of the frequency
dependences of the reflection and transmission coefficients are performed for propagation in the part of the lithium niobate
crystal surface on which two-dimensional phononic crystals were fabricated. Forbidden zones are found in the transmission
spectra of the waves transmitted through phononic crystals. It is shown that, if the width of the incident wave beam is less
than the width of the region with the two-dimensional periodic structure (the two-dimensional phononic crystal), then a resonant
increase in the transmission coefficient arises near the center of the rejection band. 相似文献
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I. V. Kubasov A. V. Popov A. S. Bykova A. A. Temirov A. M. Kislyuk R. N. Zhukov D. A. Kiselev M. V. Chichkov M. D. Malinkovich Yu. N. Parkhomenko 《Russian Microelectronics》2017,46(8):557-563
Bidomain single crystals of lithium niobate (LiNbO3) and lithium tantalate (LiTaO3) are promising materials for use as actuators, mechanoelectrical transducers, and sensors capable of working in a wide temperature range. One need to take into account the anisotropy of the properties of the crystalline material when such devices are designed. In this study we investigated deformations of bidomain round shaped Y + 128°-cut wafers of lithium niobate in an external electric field. The dependences of the piezoelectric coefficients on the rotation angles were calculated for lithium niobate and lithium tantalate and plotted for the crystal cuts which are used for the formation of a bidomain ferroelectric structure. In the experiment, we utilized an external heating method and long-time annealing with the lithium out-diffusion method in order to create round bidomain lithium niobate wafers. Optical microscopy was used to obtain the dependences of the bidomain crystals’ movements on the rotation angle with central fastening and the application of an external electric field. We also modelled the shape of the deformed bidomain wafer with the suggestion that the edge movement depends on the radial distance to the fastening point quadratically. In conclusion, we revealed that the bidomain Y + 128°-cut lithium niobate wafer exhibits a saddle-like deformation when a DC electric field is applied. 相似文献
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用cw-Ti:sapphire激光对不同组成的熔体中生长得到的铌酸钾锂晶体进行了倍频性能研究。实验结果表明,只有当晶体中Li离子含量达到一定值时,铌酸钾锂晶体才具有非线性光学效应;晶体中Li离子含量越高,倍频性能越好,Li2O浓度为26mol%的熔体中生长得到的铌酸钾锂晶体的倍频实验的结果表明,该晶体能对820-960nm的近红外cw-Ti:sapphire激光倍频实现蓝绿光输出,具有较好的倍频性能。 相似文献
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G. Kh. Kitaeva S. P. Kovalev A. N. Penin A. N. Tuchak P. V. Yakunin 《Journal of Infrared, Millimeter and Terahertz Waves》2011,32(10):1144-1156
A new method is proposed for calibration of the terahertz wave spectral brightness. The method is based on the use of quantum
and thermal field fluctuations as intrinsic references under nonlinear-optical detection. Both effective brightness of the
thermal fluctuations and temperature of the laser-pumped nonlinear-optical crystal can be measured absolutely within the calibration
procedure also. It is shown that the accuracy of the terahertz wave brightness calibration is strongly dependent on the value
of the terahertz wave losses in the nonlinear-optical crystal. The scheme of quasi-phase matched terahertz wave detection
in periodically poled lithium niobate is considered. Dispersion of the absorption coefficient in the terahertz frequency range
is measured by a three-frequency interference method under spontaneous parametric down-conversion for nominally pure and Mg-doped
lithium niobate crystals. The influence of the terahertz radiation losses in Mg-doped lithium niobate crystals is estimated. 相似文献
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Photorefractive optics in three-dimensional digital memory 总被引:2,自引:0,他引:2
Kawata S. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1999,87(12):2009-2020
To exceed the capacity limitation of the surface-recording method of current optical data storage, the third dimension is introduced with photorefractive materials. Photorefractive materials are suitable for three-dimensional data storage in conjunction with nonlinear optical systems such as the two-photon absorption process of the material for recording and the confocal laser-scanning system for reading. I will describe the systems and the materials for three-dimensional digital memory with the experimental results for read-only memory with photopolymer, erasable memory with a lithium niobate crystal and rewritable memory with photochromic organic materials. The comparison between photorefractive digital three-dimensional memory with conventional holographic three-dimensional memory and near-field memory is also discussed in terms of dynamic range, noise, recording density, and accessibility 相似文献
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Passaro V.M.N. Armenise M.N. Nesheva D. Savatinova I.T. Pun E.Y.B. 《Lightwave Technology, Journal of》2002,20(1):71-77
Proton-exchanged planar waveguides have been fabricated on Z-cut and X-cut lithium niobate crystals by using a new proton source formed by a mixture of benzoic and adipic acids. Waveguide index profiles and optical characteristics have been obtained at different values of the adipic-benzoic acid concentration ratio. The samples have been structurally characterized by Raman and infrared (IR) absorption spectroscopy and double-crystal X-ray diffraction. Good quality samples have been fabricated by using 30 mol% ratio dilution, showing very low scattering levels (<0.1 dB/cm), relatively high electrooptic coefficient (r33=0.88 pm/V), and low relative percentage of interstitial protons (26%). The main factor limiting the waveguide optical properties is the substitutional-interstitial proton ratio, which can be easily controlled to produce good quality waveguides. A demonstration of the repeatability of the exchange process in the acid mixture is also provided 相似文献