Systematic study on visible light collimation nanostructured slits in the metal surface

We present a systematic experimental investigation on visible light collimation by a nanostructured slit flanked with a pair of periodic array of grooves in gold thin film. A wide variety of aspects are considered, such as the polarization state, the transport path of incident light, the groove-groove spacing, the groove width and depth. Our results clearly show that the relationship between the collimation wavelength and the periodicity of the slit-groove structure accords well with the surface plasmon dispersion model proposed by previous researchers. Furthermore, the surface plasmon wave phase retardation effect induced by the surface structure is also verified via the measurement for samples with different groove widths and depths. These results indicate that the detailed geometry of the groove structure has obvious impacts on the collimation effect and the angular distribution of the diffraction light in the subwavelength plasmonic system.     

磁石的傅里叶变换红外光谱指纹图谱研究

对不同产地和批次的13个生磁石样品的红外光谱法进行分析,建立磁石的红外光谱指纹图谱,并将炮制品和生品进行分析比较.发现所有生磁石样品指纹图谱的相似度均大于0.97;磁石炮制后相似度和相关系数均降低.傅里叶变换红外光谱指纹图谱可用于商品磁石的分析与品质评价.     

发红色荧光铽配合物的合成及荧光性能的研究

以二苯甲酰甲烷(HDBM)为第一配体,邻菲罗啉(phen)和二吡啶并[3,2-a:2',3'-c]哇喔啉(dpq)为第二配体合成两种三元铽配合物,并进行元素分析、稀土络合滴定、摩尔电导率、红外光谱、紫外光谱、荧光激发和发射光谱的测定,推测化合物的组成分别为:Tb(DBM)3phen,Tb(DBM)3dpq.DBM通过氧...     

碳纳米管辐射太赫兹波的理论分析与数值验证

基于简单紧束缚方法理论,利用一维碳纳米管的量子化周期边界条件得到了碳纳米管的电子能级结构关系.并结合已报道的碳纳米管中电子与声子相互作用的实验结果,得到了碳纳米管能够辐射太赫兹波的结论.通过数值结果验证了碳纳米管在外场作用下能够产生太赫兹波,并对数值计算结果中太赫兹波的振荡现象给予合理的解释.其结果为进行碳纳米管产生太赫兹辐射的实验研究提供深入的理论基础. 关键词： 太赫兹波 碳纳米管     

铒离子注入碳化硅的射程和退火行为研究

用300—500 keV能量的铒(Er)离子注入碳化硅(6H-SiC)晶体中,利用卢瑟福背散射技术研究了剂量为5×10¹⁵ cm^-2 的Er离子注入6H-SiC晶体的平均投影射程R_p和射程离散ΔR_p,将测出的实验值和TRIM软件得到的理论模拟值进行了比较,发现R_p的实验值与理论值符合较好,ΔR_p的实验值和理论值差别大一些 关键词： 离子注入 投影射程和射程离散 退火行为 卢瑟福背散射技术     

一维金属光栅的光学反射吸收

利用RCWA(rigid coupled-wave analysis)方法研究了一维金属光栅的反射特性,考察了 瑞利反常、表面等离激元驻波共振和几何共振三种共振吸收机理,分析了这三种机理的相互作用,如表面等离激元驻波共振和几何共振可以形成混合模式. 在反射式复合金属光栅中,确认了第四种共振形式,即相位共振. 数值计算表明相位共振对光学吸收的影响有两种形式: 当光栅周期大于一个波长时,相位共振导致尖锐的吸收峰,峰位在几何共振吸收峰一侧;当光栅周期小于一个波长时,相位共振导致混合模式的共振吸收峰发生劈裂. 对一维金属光栅反射特性的研究增加了对金属光栅共振吸收模式及其相互作用的认识. 关键词： 一维金属光栅 瑞利反常 表面等离激元 相位共振     

太赫兹波在一维反铁磁/电介质准周期光子晶体的传输性质

本文利用传递矩阵方法研究了电磁波倾斜入射时,一维反铁磁/电介质准周期光子晶体的透射性质.反铁磁层和电介质层按Fibonacci数列排列构成准周期光子晶体.通过数值模拟发现光子禁带中有透射峰出现, 而且随着准周期光子晶体级数的增加透射峰的数目也在增加.此外,透射峰受电介质层的介电常数、入射角度和电磁波偏振影响明显. 关键词： 反铁磁层 准周期光子晶体 太赫兹波传输性质     

Lateral cavity photonic crystal surface-emitting laser with ultralow threshold

A lateral cavity photonic crystal (PhC) surface-emitting laser is realized on a commercial epitaxial waveguide wafer without a distributed Bragg reflector first. Energy is coupled from the lateral resonance to surface-emitting light through the Γ band edge of the PhC with a square lattice. Electrically driven 1553.8?nm surface-emitting lasing action is observed at room temperature. The threshold current density of 667?A/cm2 is ultralow for the surface-emitting laser.     

Improved surface-enhanced Raman scattering of patterned gold nanoparticles deposited on silicon nanoporous pillar arrays

Large-area silicon nanoporous pillar arrays (Si-NPA) uniformly coated with gold nanoparticles was synthesized, and surface-enhanced Raman scattering of rhodamine 6G adsorbed on these gold nanoparticles were studied and compared. It's found that Au/Si-NPA substrate has a significantly high Raman signal sensitivity and good homogeneity. These are attributed to gold nanoparticles with narrow particle-size distribution uniformly coated on the surface and to the enlarged specific surface area for adsorption of target molecules brought by the porous silicon pillars.     

A novel method for improving the adhesion strength of the electrodeposited Ni films in MEMS

Adhesion performance of MEMS materials is increasingly important with the widely use of miniaturized devices. This paper proposed a novel method for improving adhesion performance between electrodeposited Ni multi-layers. The new method is to treat the Ni substrate in nickel chloride plating solution by pulse reverse current technique before electrodeposition. The dense oxide film of Ni substrate can be removed effectively by this electrochemical method, meanwhile, the proper roughness of Ni substrate is in favor of epitaxial growth during electrodeposition. Moreover, the Ni film is electrodeposited by the new method with low stress and coarse crystal grain. Consequently, the adhesion performance of Ni films is improved dramatically. The experimental results show that the adhesion performance of Ni film electrodeposited by the new method is about 3 times that of by traditional method.