COMPETITION BETWEEN SELF-PUMPED AND MUTUALLY-PUMPED PHASE CONJUGATIONS IN A BaTiO3 BRIDGE PHASE CONJUGATOR

This paper reveals the inter-dependence and the competition between self-pumped and mutually-pumped phase conjugations, and deals with the periodic instabilities in the phase conjugate output of a BaTiO₃ bridge phase conjugator. It presents experimental data demon-strating these instabilities and also gives evidence that the addition of the second heam in a bridge phase conjugator can affect the self-pumping threshold for the first beam. A mathe-matical model is developed to explain the observed output oscillations.     

BaTiO3晶体自抽运相位共轭特性研究

研究了多种Rh:BaTiO3和Ce:BaTiO3晶体样品的受激背向光折变散射自抽运相位共轭特性和响应时间特性.结果表明,入射光与晶体a面或b面法线的夹角较大时,自抽运相位共轭光有更高的反射率、更快响应时间.利用前向二波耦合特性和相向二波耦合特性对实验现象给予合理的解释.实验结果表明,多数Ce:BaTiO3晶体比Rh:BaTiO3晶体的共轭光反射率高.     

利用光感应自泵浦方法实现图象的色彩转换

首次报道一种利用光折变晶体的光感应自泵浦实现图象色彩转换的方法。用此方法可得到具有相位共轭的正转换图象,其分辩率可达到281p/mm,同样的方法可用于将非相干图象转换成相干图象。     

BaTiO3晶体自抽运相位共轭特性研究

研究了多种Rh:BaTiO₃和Ce:BaTiO₃晶体样品的受激背向光折变散射自抽运相位共轭特性和响应时间特性.结果表明,入射光与晶体a面或b面法线的夹角较大时,自抽运相位共轭光有更高的反射率、更快响应时间.利用前向二波耦合特性和相向二波耦合特性对实验现象给予合理的解释.实验结果表明,多数Ce:BaTiO₃晶体比Rh:BaTiO₃晶体的共轭光反射率高. 关键词： 钛酸钡晶体 二波耦合 自抽运相位共轭 响应时间     

A CONTINUOUS COMPOUND FOUR-WAVE MIXING MECHANISM FOR SELF-PUMPED PHASE CONJUGATION IN BaTiO3 CRYSTALS

A continuous compound four-wave mixing mechanism for sell-pumped phase conjugation in photorefractive crystals is presented. The coupled-beam equations of this mechanism are solved numerically when depletion of the forward going beam is neglected. The experiment in a Ce-doped BaTiO₃ crystal is performed, with the stable phase conjugate reflectivity of as much as ≥80%. The curved high output phase conjugate intensity are explained using the numerical results.     

TEMPORAL BEHAVIOR OF PHASE-CONJUGATE OUTPUTS IN A COHERENTLY INDUCED PHASE CONJUGATOR

The temporal behavior of the bidirectional phase-conjugate outputs from a coherently induced phase conjugator has been observed on a Cu-doped barium strontium potassium sodium niobate crystal. In our experiment, the phase-conjugate outputs of two incident beams vary smoothly with time if the beam ratio is large. When the beam ratio is reduced, however, each phase conjugate output will experience a temporal fluctuation. The phase-conjugate output characteristic is found to be dependent on the beam ratio of the two input beams, their positions, their beam-path-length difference and sometimes the input order of the two beams. We present a model of multi-region-interaction to explain the operation of the device and the experimental results in this paper.     

A CONTINUOUS COMPOUND FOUR-WAVE MIXING MECHANISM FOR SELF-PUMPED PHASE CONJUGATION IN BaTiO3 CRYSTALS

A continuous compound four-wave mixing mechanism for sell-pumped phase conjugation in photorefractive crystals is presented. The coupled-beam equations of this mechanism are solved numerically when depletion of the forward going beam is neglected. The experiment in a Ce-doped BaTiO₃ crystal is performed, with the stable phase conjugate reflectivity of as much as ≥80%. The curved high output phase conjugate intensity are explained using the numerical results.     

Bery相与AB相的关系

Ｂｅｒｒｙ曾经论证，Ａｈａｒｏｎｏｖ-Ｂｏｈｍ相可以看成是Ｂｅｒｙ相．在论证中放弃了绝热近似，也未涉及量子态的非定态性．重新探讨了此论证，表明Ｂｅｒｙ的结论是正确的，但在该论证过程中需要作绝热近似．ＡＢ效应中运动电子是用一个运动波包（非定态）来描述的，ＡＢ相的出现，是要求波包的演化必须满足Ｓｃｈｒ?ｄｉｎｇｅｒ方程的结果，但ＡＢ相的出现不受绝热条件的限制 关键词：     

Cu∶KNSBN晶体自泵浦与互泵浦相位共轭共存特性的实验研究

利用Cu∶KNSBN晶体,研究了在两束泵浦光对称入射的条件下,自泵浦与互泵浦相位共轭共存时相互竞争和相互影响的特性,以及共存时的相位共轭特性与两束泵浦光的入射位置、入射夹角和泵浦比之间的关系,并对自泵浦相位共轭反射率和两束泵浦光共同存在条件下的自泵浦相位共轭反射率进行了比较.     

Na6团簇2D和3D结构的竞争

在距离相关紧密结合分子动力学模型的基础上，对Ｎａ６两个最低能量异构体（一个具有Ｃ５ｖ对称性，是３Ｄ结构，另一个具有Ｄ３ｈ对称性，是２Ｄ结构）的结构性质进行了研究。通过求解Ｈｅｓｉａｎ矩阵和对距离相关紧密结合分子动力学轨道所作的速度自关联函数的福里叶变换分析，得到了这些钠原子微团簇的振动频率。尽管这两种结构的能量很接近，但它们表现出完全不同的振动性质，这反映了其几何结构的差别。     

Cu:KNSBN晶体自泵浦与互泵浦相位共轭共存特性的实验研究

利用Cu:KNSBN晶体,研究了在两束泵浦光对称入射的条件下,自泵浦与互泵浦相位共轭共存时相互竞争和相互影响的特性,以及共存时的相位共轭特性与两束泵浦光的入射位置、入射夹角和泵浦比之间的关系,并对自泵浦相位共轭反射率和两束泵浦光共同存在条件下的自泵浦相位共轭反射率进行了比较.     

INFLUENCE OF BEAM POLARIZATION ON THE PERFORMANCE OF A MUTUALLY PUMPED PHASE CONJUGATOR

The influence of polarization variation of a pump beam on the performance of a “bridge” mutually pumped phase conjugator has been investigated. The reflectivity, transmission, and response time were measured for different polarizations and different intensity rations of input beams. From these measured results, the variation behaviors of parameters of fourwave mixing interactions in the crystal are revealed.     

钛酸锶钡的铁电相变与晶胞体积的关联

考察了Ba_μSr_1-μTiO₃(BST)的T_C对晶格 参数γ的依赖关系.并对BST的依赖关系与BaTiO₃和SrTiO₃的相应依 赖关系进行了比较.得到了一个观点：BST的T_C的变化可归因于晶胞体积效应.还 从体积效应的观点对BST相变的弥散性和级进行了讨论.BST的晶胞体积效应可归因于BST中Ba 和Sr的离子化现象. 关键词： 铁电性 钛酸锶钡 晶胞体积效应     

光折变“波导”诱失锁模ps激光脉冲自泵浦相位共轭

观察到失锁模５３２ｎｍｐｓ激光脉冲单独入射到掺Ｃｕ的ＫＮＳＢＮ晶体中，不能产生自泵浦相位共轭，但如果先用同波长的锁模ｐｓ激光脉冲在晶体中预制一条光折变“波导”，则可诱导失锁模激光脉冲形成自泵浦相位共轭．分别从“波导”形成和时间分辨光谱等方面研究了这一现象 关键词：     

孤子传输中的喇曼自泵产生及其对孤子传输的影响

本文采用分步傅氏变换方法对考虑交叉非线性项的孤子及其喇曼自泵光的传输方程进行了数值研究,得出了喇曼自泵光产生及其对孤子传输影响的几个一般结论。这些结论对孤子通信问题具有一定的意义。     

长脉冲自由电子激光中模的竞争与饱和

本文给出了长脉冲自由电子激光中模的竞争与饱和的统一描述;证明了多模经过竞争趋向于单模;得到系统达到饱和点时的饱和参数值和饱和功率的标度以及饱和点后的同步振荡。     

内锡法Nb3Sn超导线A15相组成及TC的特征研究（英文）

设计并制备四组不同组成的内锡法Nb3Sn单组元线和两组不同结构设计的多芯线.先将所有样品进行210℃/50hr+340℃/25hr的Cu-Sn合金化热处理,接着进行A15相成相热处理.四组单组元线的成相热处理程序是在675oC,700oC和725℃三种温度下热处理100小时和200小时;而两组多芯线的成相热处理程序是在675℃,675℃,700℃和725℃四种温度下热处理128小时和200小时.将所有热处理样品采用X-射线EDS进行A15相组成分布测定,采用SQUID磁化法测定临界温度TC.所得结果表明,经过足够热处理时间后各种内锡法Nb3Sn超导线的最终A15相组成和TC与热处理温度、导线复合体组成和结构设计以及第三元素的合金化掺杂无关,而是由这种扩散与固相反应的机制本质所决定的.     

LaAlO3晶体中相变与缺陷研究

从室温到800℃范围内用锥光干涉图实时观察LaAlO₃晶体中的相变,发现在560℃存在由三角相转变为立方相的相变,并由X射线衍射法得到证实,同时对孪晶的形态,畴区的结晶学取向规律,孪晶的密集度以及畴和包裹体的双折射像在T_c附近的变化规律进行了系统的研究。 关键词：     

关于量子不变量及其与量子相位关系的几点注记

基于量子不变量构造定理，简化地导出和扩充了Lewis和Riesenfeld的结果．指出所谓的Lewis-Riesenfeld相位一般没有物理意义；为了使其有物理意义，不变量必须取特殊形式．文中给出了这种形式．以磁场中的自旋系统为例，作了具体讨论． 关键词：     

MOVING GRATING AND ITS PHASE SHIFT IN LiNbO_3:Fe CRYSTAL

Spatial phase shift of moving grating in LiNbO_3:Fe crystal iscalculated on the basis of photorefractive dynamic equations.It is shown that themoving grating is a self-established phase grating that generates backward dynamiclight scattering.