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采用K2O作助熔剂直接拉晶法和气相输运平衡技术制备出了高质量近化学计量比铌酸锂晶体,研究了铌酸锂晶体中的[Li][Nb]比含量对其畴反转结构和极化电场的影响.实验结果表明:随着晶体中[Li][Nb]比的提高,畴极化反转电场呈明显下降趋势,使用近化学计量比铌酸锂晶体,在4.0±0.5kVmm大小极化电场条件下,成功地实现了1.0mm厚度的周期极化畴反转.并用铌酸锂晶体的Li空位缺陷模型对上述实验结果给出了合理的解释.
关键词:
近化学计量比铌酸锂晶体
周期极化
畴反转 相似文献
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通对周期性极化铌酸锂(periodically poled lithium niobate,PPLN)的微区拉曼和荧光研究,发现小极化子荧光在反转畴与非反转畴呈现不同强度,同时在畴分界壁观察到拉曼禁止谱线.提出一种能够呈现极化光畴图像的非损伤方法,并进一步探讨反向极化过程的机理.
关键词:
周期性极化铌酸锂
微区拉曼
极化子荧光 相似文献
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报道基于6mol%镁掺杂的周期性畴反转掺镁铌酸锂(PPMgLN)的宽调谐光参量振荡器(OPO). PPMgLN采用外加电场法制作,周期为27.8—31.6μm,周期间隔为0.2μm.光参量振荡器的抽运源采用输出为1.064μm的声光调Q的Nd3+:YVO4激光器,其调谐范围为1.42—1.73μm(信号光)和2.76—4.27μm(闲散光),斜率效率达到47%.在输入功率为10.6W时,输出功率达到4.8W(信号光和闲散光之和).
关键词:
周期性畴极化掺镁铌酸锂
宽调谐光参量振荡器 相似文献
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利用马赫-曾德尔干涉光路和4f光学透镜系统,以部分畴反转的掺钌铌酸锂晶体(RuO2:LiNbO3)的透射光作为物光来记录全息图,并在数值再现过程对其进行频域滤波以实现物场波前信息的数值重建,检测出在一定电压作用下晶体内部折射率变化的二维分布.检测结果证实:晶体中发生畴反转的区域与发生电色效应的区域严格相符.数字全息干涉术非接触、无干扰、无破坏的优势在准实时监控、检测和分析铌酸锂晶体畴反转方面有很好的应用前景.
关键词:
畴反转
数字全息干涉术
电色效应 相似文献
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Doping MgO, MnO and Fe2O3 in LiNbO3 crystals, tri-doped Mg:Mn:Fe:LiNbO3 single crystals were prepared by the conventional Czochralski method. The UV-vis absorption spectra were measured and the shift mechanism of absorption edge was also investigated in this paper. In Mg:Mn:Fe:LiNbO3 crystal, Mn and Fe locate at the deep level and the shallow level, respectively. The two-photon holographic storage is realized in Mg:Mn:Fe:LiNbO3 crystals by using He-Ne laser as the light source and ultraviolet as the gating light. The results indicated that the recording time can be significantly reduced for introducing Mg2+ in the Mg:Mn:Fe:LiNbO3 crystal. 相似文献
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Mg2+对Fe:LiNbO3晶体光折变响应时间的影响 总被引:3,自引:3,他引:0
在Fe:LiNbO3中掺进3mol%和6mol%MgO,生长了Mg:Fe:LiNbO3晶体.测试了Mg:Fe:LiNbO3晶体抗光致散射能力、衍射效率、响应时间和光电导.推导响应时间与光电导之间的关系.在Fe:LiNbO3晶体中掺进6mol%的Mg2+,它的抗光致散射能力比Fe:LiNbO3晶体提高一个数量级,响应速度比Fe:LiNbO3晶体提高四倍. 相似文献
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LiNbO 3 has been found attractive for lateral field excitation (LFE) applications due to its high piezoelectric coupling. In this paper, bulk acoustic wave propagation properties for LiNbO 3 single crystal excited by a lateral electric field have been investigated using the extended Christoffel-Bechmann method. It is found that the LFE piezoelectric coupling factor for c mode reaches its maximum value of 95.46% when ψ = 0 for both (yxl)-58 and (yxwl)±60 /58 LiNbO 3 . The acoustic wave phase velocity of c mode TSM (thickness shear mode) changes from 3456 m/s to 3983 m/s as a function of ψ. Here ψ represents the angle between the lateral electric field and the crystallographic X-axis in the substrate major surface. A 5 MHz LFE device of (yxl)-58 LiNbO 3 with ψ = 0 was designed and tested in air. A major resonance peak was observed with the motional resistance as low as 17 and the Q-factor value up to 10353. The test result is well in agreement with the theoretical analysis, and suggests that the LFE LiNbO 3 device can be a good platform for high performance resonator or sensor applications. 相似文献
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We present a Judd-Ofelt spectroscopic analysis on the Mg/Er-codoped congruent lithium niobate (LiNbO3) crystals. The Judd-Ofelt model is applied to the room temperature unpolarized absorption intensities of Er3+ ions on eleven transition bands to determine their intensity parameters: Ω2=2.36×10−20 cm2, Ω4=0.76×10−20 cm2, Ω6=0.30×10−20 cm2 in Er:LiNbO3 crystal heavily codoped with MgO. The radiative lifetime of 2H9/2 becomes longer when MgO is added into Er:LiNbO3 crystal. The experimental lifetimes are obtained using microsecond time-resolved spectra at 400 nm femtosecond pulse excitation to predict radiative quantum efficiency. Combining higher radiative quantum efficiency with longer radiative lifetime, we conclude that Mg/Er-codoped LiNbO3 crystals are more suitable than Er: LiNbO3 ones in laser materials. 相似文献
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Undoped and MgO doped Lithium niobate single crystals were grown by the Czochralski technique. Comparative study of the optical properties of undoped and 7 mol% MgO doped LiNbO3 crystal was undertaken. The effect of doping on refractive indices as well as second harmonic generation has been experimentally analyzed. The results of the polarization characteristics of second harmonic generation (SHG) support the major contribution of Li-O bonds to optical nonlinearity. MgO doping reduces the number of localized excitons and the grown LiNbO3 crystal approaches the stoichiometric composition. This causes blue shift in the absorption edge of the crystals. 相似文献
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3 crystal – was grown in our Laboratory. The absorption and fluorescence spectra were measured and show some differences from
the results of common Nd:MgO:LiNbO3 with monodomain structure. Third-order quasi-phase-matched violet second-harmonic generation in the sample was demonstrated
to characterize the quality of the crystal. The properties indicate that the periodically poled optical superlattice Nd:MgO:LiNbO3 has great potential for constructing a blue or green light source through self-frequency-doubling operation using the maximum
nonlinear optical coefficient d33 of LiNbO3 and the high-gain π polarization at the same time.
Received: 22 August 1997/Revised version: 10 January 1998 相似文献
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《光谱学快报》2013,46(4):437-442
The Raman Spectra of LiNbO3:MgO (6.7 mol%) at both low temperature and room temperature were studied. The results showed that the crystal structure has changed little after doping Mg+ +. At room temperature the lattice distorted a little, which caused the appearance of coupling phenomenon of some individual scattering peaks. As the temperature decreased, the coupling reduced gradually. 相似文献
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利用气相平衡扩散法研制出掺镁不同组分的LiNbO3晶体,并对其极化特性进行了研究.研究表明晶体的开关电场和自发极化不仅与晶体组分[Li]/[Nb]比有关而且与掺镁量有关,[Li]/[Nb]比为0.973掺入2mol% MgO的近化学比LiNbO3晶体的开关电场仅为1.8kV/mm,是同成分晶体的1/12,且其极化结构的质量要远好于同成分LiNbO3晶体和近化学比LiNbO3晶体.
关键词:
气相平衡扩散
3晶体')" href="#">掺镁LiNbO3晶体
周期极化 相似文献
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Zuo Xiaoxi 《Optik》2005,116(7):361-364
Fe:LiNbO3 and In:Fe:LiNbO3 crystals were grown by Czochralski method. The absorption spectra were measured to investigate their defect structure. The photo damage resistance and photorefractive properties were measured. The photo damage resistance of the In:Fe:LiNbO3 crystal in which the In concentration is above the threshold value is one order of magnitude higher than that of the Fe:LiNbO3 crystal. The mechanisms of the violet shift of the absorption edge and the enhancement of the photorefractive effect of In:Fe:LiNbO3 crystals were investigated. 相似文献
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A series of Mg:Ce:Cu:LiNbO3 crystals has been grown by Czochralski method. Their infrared transmittance spectra and ultraviolet-visible absorption spectra were measured and discussed to investigate their defect structure. The nonvolatile holographic recording of Mg:Ce:Cu:LiNbO3 crystals was characterized by the two-photon fixed method. We found that the recording time of Mg:Ce:Cu:LiNbO3 crystals became shorter and nonvolatile diffraction efficiency decreases with the increase of Mg doping concentration, especially doping with Mg approaches and exceeds the so-called threshold. And the nonvolatility vanishes when the concentration of MgO exceeds 4 mol%. The intrinsic and extrinsic defects were discussed to explain the nonvolatile holographic properties in the Mg:Ce:Cu:LiNbO3 crystals. 相似文献