超强脉冲激光在低密度等离子体中的相对论自导引效应

分析了相对论条件下激光超短脉冲在等离子体中的传输特性 ,在傍轴近似和慢变振幅近似条件下 ,推导了折射率、电子密度、静电场以及电子空腔尺度的表达式。当激光功率超过产生自导引阈值功率时 ,激光束斑沿着传输光轴方向振荡。在有质动力产生的压力非常强时 ,聚焦光束中央部分的电子被全部排开形成电子空腔。给出了电子空腔的尺寸以及在出现电子空腔时的处理方法。在超过形成电子空腔的阈值功率 (Pc≈ 2 .5TW )时 ,空腔的尺度几乎与激光功率无关 ,这意味着电子空腔阻止了激光脉冲的进一步聚焦。     

串联双环光微谐振器的滤波特性

详细研究了串联双环光微谐振器的光带通滤波特性，给出了其通带带宽的公式，分析了出／入环光耦合系数和环间光耦合系数对通带特性的影响，计算并特别强调了滤波通带的结构特点，也分析了微环中存在的光损耗对串联双环光微谐振器的滤波特性的影响。     

微波谐振腔Q值对磁激子振幅不稳定态阈值的影响

基于Safonov和Yamazaki所发展的激励自旋波非线性辐射衰减的理论［J. MMM. 161 (1996 ) 275］, 考虑磁激子与磁激子以及磁激子与光子的两种非线性相互作用过程，计算了微波谐振腔Q值对磁激子振幅不稳定态阈值的影响，结果与实验数据基本一致. 关键词： 磁激子 谐振器 铁磁体     

Quantum State Transfer between Two Distant Atoms by Connecting Two Cavities via Optical Fibres

A scheme is proposed to unconditionally implement state transfer between two distant atoms by sending the atoms across two distant cavities connected via an optical fibre, respectively. The field state, which preserves the information about the first atom, is transmitted from one cavity to the other along the fibre. A Faraday rotator integrated in the fibre can be designed to completely stop the fields reflected from the second cavity, thus after the field interacts with the second atom for a defined time, the state transfer can be accomplished with unit efficiency.     

聚合物微腔的研制及其特性分析

采用ＢＭＰＰＶ：ＰＶＫ的混合物作国源介质，将其按一定比例溶于氯仿中，并旋涂在具有９９．５％的反射率的ＤＢＲ上，其上蒸发３００ｎｍ的银膜，形成了面发射型微腔结构，其中ＤＢＲ在入射腔面，银膜为反射腔面，在激发波长３３７．１ｎｍ，频率２０Ｈｚ脉宽１０ｎｓ的氮分子激光器泵浦下，光谱明显等窄化，出现４６０ｎｍ和５３０ｎｍ两个比较强的发光峰，主峰国４６０ｎｍ半宽度为７ｎｍ。     

无机盐对β-环糊精空腔微环境影响的荧光探针研究

基于芘的单体荧光光谱振动结构与其所处环境极性的相关性, 研究了碱金属氯化物对β-环糊精(β-CD)空腔微环境的影响。盐类的引入导致β-CD空腔极性减小, 芘/β-CD包络物形成常数增大。结果表明疏水相互作用是包络物形成动力之一; 盐类的引入除改变溶液的离子强度, 还与β-CD分子间存在着特殊的相互作用, 后者是导致环糊精空腔性质变化的根本原因。详细探讨了盐与β-CD分子间的作用本质。     

不同电极数石英谐振器集群力敏特性分析

为了提高石英力敏谐振器的力-频转换系数,根据石英晶体压电效应及各向异性特性,利用Matlab数值计算方法,研究了径向力作用时AT切石英晶体薄圆片内各点的应力分布特点,设计了不同基频及不同电极数的石英力敏谐振器集群,并对其力敏特性进行了测试。结果表明:谐振器的力敏特性与谐振器的谐振频率、电极位置及力作用方位有关;集成于同一晶体基片不同位置的谐振器谐振频率作差频处理,得到的差频信号仍具有显著的力敏特性,同时差频信号中材料自身干扰因素的影响得到了抑制;在非耦合状态下,同一晶体基片上电极集成数越多,差频组合形式越多,得到的叠加信号的力敏特性越显著;经差频及叠加处理,集成式石英六电极谐振器的力-频转换系数可达8655.8 Hz/N。这种结构的力敏谐振器可用于高稳定的数字式力传感器及相关姿态检测控制系统。     

Entanglement Purification for Mixed Entangled Quantum Dot States via Superconducing Transmission Line Resonators

An entanglement purification protocol for mixed entangled states is presented via double quantum dot molecules inside a superconducing transmission line resonator （TLR）. In the current scenario, coupling for arbitrary double quantum dot molecules can be tuned via the TLR in the large detuning region by controlling the qubit level splitting. The TLR is always empty and only virtually excited, so the interaction is insensitive to both the TLR decay and thermal field. Discussion about the feasibility of our scheme shows that the entanglement purification can be implemented with high fidelity and successful probability.     

Cavity-enhanced laser cooling of solid-state materials in a standing-wave cavity

We propose a new method to cool the yb^3＋-doped ZBLANP glass in a standing-wave cavity. There are two advantages of this cavity-enhanced technique： the pumping power is greatly enhanced and the absorption of the cooling material is greatly increased. We introduce the basic principle of the cavity-enhanced laser cooling and discuss the cooling effect of a solid-state material in a cavity. From the theoretical study, it is found that the laser cooling effect is strongly dependent on the reflectivity of the cavity mirrors, the length of the solid material, the surface scattering of the material, and so on. Some optimal parameters for efficient laser cooling are obtained.