共查询到16条相似文献,搜索用时 125 毫秒
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利用外加电场极化的方法,分别研究了三种不同方式布置的极化电极对C向切割LiNbO3< /sub>晶体极化反转畴扩张的影响.实验结果表明在相同极化条件下,当极化电极长度方向与六边 形反转畴一对边呈90°和0°角时,极化扩张速度分别为0.089μm/ms和0.011μm/ms.实验结果揭示,为了有效地控制极化占空比,在制备一维准相位匹配LiNbO3晶体时应 避免极化电极与六边形反转畴壁中一对边呈90°的情况.
关键词:
周期极化
极化扩张
准相位匹配 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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量子纠缠是量子信息领域的核心资源,目前利用β型硼酸钡(BBO)晶体参量下转换制备的纠缠光子对的亮度较低,它直接制约了量子通信的最远距离,已无法满足星地实用化量子通信的发展需求.利用周期极化KTiOPO4晶体,采用准相位匹配技术设计产生了一种后选择的纠缠源,测得的符合计数达到了16×103s-1 mW-1,极化对比度达到27∶1,在亮度上比基于BBO的量子纠缠光源提高了一个数量级以上.这一高亮度的纠缠源可以广泛应用于量子密钥分发、量子隐形传态以及量子计算等新兴量子信息领域,为实现全球化量子通信提供了有力的保障.
关键词:
纠缠态
准相位匹配
4晶体')" href="#">周期极化KTiOPO4晶体 相似文献
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A. Yu. Milinskiy E. V. Stukova 《Bulletin of the Russian Academy of Sciences: Physics》2016,80(9):1089-1091
Linear and nonlinear dielectric properties of KIO3 polycrystalline samples are investigated. It is shown that linear dielectric permittivity ε' displays four anomalies corresponding to phase transitions in KIO3. Anomalies of third-harmonic coefficient γ3ω are observed at temperatures of 113, 263, and 345 K, corresponding to phase transitions between KIO3 ferroelectric phases. It is established that the third-harmonic coefficient responsible for the nonlinearity of dielectric properties displays no anomalies during the transition to the paraelectric phase of KIO3 at approximately 485 K. Possible reasons for there being no such anomaly are discussed. 相似文献
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《Journal of magnetism and magnetic materials》2002,238(2-3):140-144
Optical reflectivity studies of the ferromagnetic metal (FMM) to antiferromagnetic insulator (AFI) phase transition were performed on Nd0.5Sr0.5MnO3 single crystals in a wide temperature and magnetic field range. The formation of a domain structure in the AFI state was observed. On the basis of the experimental results and symmetry analysis we conclude that these domains are crystal twins, confirming the symmetry lowering of the crystal at this phase transition. The twin domain structure of the AFI state in the Nd0.5Sr0.5MnO3 is visible in reflected unpolarized light due to a different tilting of the surface of the domains. We find no evidence for intermediate FMM+AFI stripe phase. 相似文献
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Optical diffraction is reviewed as a technique for investigation of the phase transitions in crystals with a multidomain structure. It has been used to study the phase transitions in KIO3 and KNbO3 single crystals. Strong optical diffraction bands resulted from electric domains in KNbO3 crystals and their change with temperature were observed when a laser beam passed through the crystals. The diffraction patterns observed changed abruptly at 427°C, 223°C, and -50°C respectively, at which KNbO3 crystals undergo structural phase transitions. It is considered that the change of the diffraction patterns with temperature is due to change of the electric domains in the crystals. 相似文献
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K. Kuwahara K. Iwasa M. Kohgi N. Aso M. Sera F. Iga M. Matsuura K. Hirota 《Physica B: Condensed Matter》2009,404(17):2527
Recently, in phase IV of CexLa1-xB6, weak but distinct superlattice reflections from the order parameter of phase IV have been detected by our unpolarized neutron scattering experiment [K. Kuwahara, K. Iwasa, M. Kohgi, N. Aso, M. Sera, F. Iga, J. Phys. Soc. Japan 76 (2007) 093702]. The scattering vector dependence of the intensity of superlattice reflections is quite unusual; the intensity is stronger for high scattering vectors. This result strongly indicates that the order parameter of phase IV is the magnetic octupole. However, the possibility that the observed superlattice reflections are due to lattice distortions could not be completely ruled out only on the basis of the unpolarized neutron scattering experiment. To confirm that the superlattice reflections are magnetic, therefore, we have performed a single crystal polarized neutron diffraction experiment on Ce0.7La0.3B6. The obtained result has clearly shown that the time reversal symmetry is broken by the order parameter of phase IV. This is further evidence for the magnetic octupole order in CexLa1-xB6. 相似文献
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研究了Yb:KLu(WO4)2晶体对非偏振抽运光的吸收以及连续波激光振荡性质. 晶体结构的低对称性导致晶体光谱呈强烈各向异性,最强的吸收和发射都发生在平行于Nm主轴的偏振方向上. Ng切向晶体具有最高的非偏振抽运光吸收效率和最大的激光功率产生潜力,2 mm长的晶体产生的最高连续波输出功率为11 W,相对于吸收抽运功率,光—光转换效率为68%,而斜率效率则达80%.
关键词:
吸收谱
发射谱
激光振荡
各向异性 相似文献