有序混合光束和迷宫式多次反射光学系统

本文给出有序混合光束结构和多程光学系统的具体考虑,并指出它们在多波长高激发态激光光谱学研究和其它领域中的意义.     

Removal of water adsorbed on flouride glass surfaces by NF3 plasma processing

A new method to remove water adsorbed on flouride glass preforms is reported. This method, using NF₃ plasma, can remove surface water on fluoride glasses     

离子注入SiO_2玻璃的光吸收研究

本文用卢瑟福背散射和光吸收技术研究了高剂量Ag离子注入SiO_2玻璃以及退火后的状况.吸收光谱测量表明,注入的Ag离子聚集形成了胶态粒子,其等离子共振峰的极大值在400nm处.运用米(Mie)理论和德拜(Doyle)方法,根据测得的等离子共振峰的光宽度,估算出Ag胶态粒子的半径约为18(?).     

金属银极薄薄膜的光学特性

本文根据可见光区域测量的不同厚度,不同稳定情况下Ag膜透过率光谱响应曲线,结合岛状金属膜有效介质理论,讨论了Ag膜中类自由电子和束缚电子引起的等效洛伦兹振子和带间跃迁随厚度和稳定时间的变化规律。理论计算的透过率曲线与实验符合得很好。比较理论与实验,得到了不同厚度下、不同稳定情况Ag膜的光学常数。     

Brewster-angle cut doubled light shutter

New types of doubled electro-optic, and low voltage controlled doubled elasto-optic light shutters containing Brewster-angle cut crystals instead of separate polarizers are investigated. Light transmission characteristics show that the devices without polarizers can give a modulation depth of about 20%.     

MgO缺陷和不规则表面吸附Cl2的电子结构研究

采用从头算程序对MgO表面 3种不同配位位置吸附Cl2 的构型进行优化 ,并用扩展休克尔紧束缚 (EHT)晶体轨道方法对MgO的缺陷和不规则表面吸附Cl2的可能构型进行能带计算 ,讨论了吸附前后能带组成和成键性质的变化。研究表明 :MgO表面吸附Cl2 将更趋向于吸附在O原子上而非Mg原子上 ,而且在 3种配位中MgO表面三配位氧最有利于吸附Cl2 ;吸附时 ,电子从O原子转移到Cl2 分子的反键轨道 ,但是各种吸附构型的MgO表面对Cl2 的吸附作用均比较微弱 ,是典型的物理吸附。     

两端对称负折射率缺陷复合光子晶体:多通道滤波和光开关

采用传输矩阵法对两端对称负折射率缺陷复合光子晶体结构[D(AB)mD]N的透射特性进行了研究.结果表明:当N=2时,该结构透射谱的禁带出现两个完全共振透射峰,当N增加时,每个共振透射峰又分裂为N-1条；当复合光子晶体的层数m逐渐增加时,透射峰的品质因子逐渐提高,且分裂的共振透射峰距离逐渐减少；既为该结构实现高品质的多通...     

Quantum phase transitions of fermionic atoms in an anisotropic triangular optical lattice

The effect of anisotropy caused by a confining potential on the properties of fermionic cold atoms in a triangular optical lattice is systematically investigated by using the dynamical cluster approximation combined with the continuous time quantum Monte–Carlo algorithm.The quantum phase diagrams which reflect the temperature–interaction relation and the competition between the anisotropic parameter and the interaction are presented with full consideration of the anisotropy of the system.Our results show that the system undergoes a transition from Fermi liquid to Mott insulator when the repulsive interaction reaches a critical value.The Kondo effect also can be observed in this system and the pseudogap is suppressed at low temperatures due to the Kondo effect.A feasible experiment protocol to observe these phenomena in an anisotropic triangular optical lattice with cold atoms is proposed,in which the hopping terms are closely related to the lattice confining potential and the atomic interaction can be adjusted via the Feshbach resonance.     

干细胞迁移机理的近场扫描光学显微术研究

将内皮细胞生长因子(VEGF)置于甲基纤维素碟中形成VEGF的浓度梯度分布,并将人脐带间充质干细胞(Mesenchymal stem cells,MSCs)于此浓度梯度中培养,观察VEGF能否诱导MSCs定向迁移。应用近场扫描光学显微术(Near-field scanning optical microscopy,NSOM)同时获取了VEGF诱导前后的MSCs的形貌和光学信息。结果表明,近场光学图观测到形貌图上所没有的黑色斑点,分析认为这些黑斑为细胞的黏着斑。近场光学图显示经过VEGF诱导后细胞的黏着斑数量明显增加。同时,对诱导前后干细胞的骨架蛋白进行免疫荧光标记并用共聚焦显微镜进行观察,结果表明细胞骨架由诱导前的无序状态转变为诱导后的有序状态,说明诱导后的干细胞处于迁移状态。光学超微结构图则显示了诱导后干细胞表面的光学细节比诱导前细胞大量增加,出现了大量直径约200 nm的光斑,这是由于细胞表面大量分泌黏附分子等蛋白分子引起的,这些结果为VEGF能够诱导MSCs进行定向迁移提供了实验依据和可视化证明。也表明NSOM不但能提供高分辨的光学分辨率,还可提供生物细胞精细结构的更深层次的光学信息。     

Resilient collapse of thermal sensitive polymer on the surface of the optical fiber taper

In this work, collapse of poly(N‐isopropyl‐acrylamide) (pNIPAM) grafted on the surface of the optical fiber taper is probed by measuring fluorescence of rhodamine B solution at various temperatures. It is observed that the fluorescence intensity through the taper shows a nonlinear response to temperature. According to the optical model for the special designed taper, it is realized that the nonlinear response results from changing in effective refractive index of interfacial layer between taper and solution. Analysis on relationship between signal change and collapse process reveals a springback process during the collapse of pNIPAM chains. Such a novel phenomenon is further investigated on method for fluorescence measurement and molecular weight of the polymer. These results have not only revealed details of the collapse, but also establish a novel technique for study the collapse of thermal sensitive polymers on the surface. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 778–785