Optical Properties of a New Two-photon Absorption Dye DEASPI

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｔｗｏ ｐｈｏｔｏｎａｂｓｏｒｐｔｉｏｎ (ＴＰＡ)ｉｓａｐｒｏｃｅｓｓｉｎｗｈｉｃｈｔｗｏｐｈｏｔｏｎｓａｒｅｓｉｍｕｌｔａｎｅｏｕｓｌｙａｂｓｏｒｂｅｄｔｏａｎｅｘｃｉｔｅｄｓｔａｔｅｉｎａｍｅｄｉｕｍｖｉａａｖｉｒｔｕａｌｓｔａｔｅ .ＴＰＡｉｎｔｅｎｓｉｔｙｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙＴＰＡｃｒｏｓｓｓｅｃｔｉｏｎ .ＳｕｃｈｍａｔｅｒｉａｌｓｗｉｔｈｌａｒｇｅＴＰＡｃｒｏｓｓｓｅｃｔｉｏｎｈａｖｅｒｅｃｅｉｖｅｄｃｏｎｓｉｄｅｒａｂｌｅａｔｔｅｎｔｉｏｎｉ…     

Introduction to Authors

ＡｉｍｓａｎｄｓｃｏｐｅＨＩＧＨＥＮＥＲＧＹＰＨＹＳＩＣＳＡＮＤＮＵＣＬＥＡＲＰＨＹＳＩＣＳｃｏｖｅｒｓｔｈｅｆｉｅｌｄｓｏｆＨｉｇｈＥｎｅｒｇｙＰｈｙｓｉｃｓ,Ｃｏｓｍｉｃ ＲａｙＰｈｙｓｉｃｓ,ＨｉｇｈＥｎｅｒｇｙＡｓｔｒｏｐｈｙｓｉｃｓ,ＩｎｔｅｒｍｅｄｉａｔｅＥｎｅｒｇｙＰｈｙｓｉｃｓ,ＮｕｃｌｅａｒＰｈｙｓｉｃｓ,ＨｅａｖｙＩｏｎＰｈｙｓｉｃｓ,Ａｃｃｅｌｅｒａｔｏｒ,Ｄｅｔｅｃ ｔｏｒａｎｄＳｙｎｃｈｒｏｔｒｏｎｒａｄｉａｔｉｏｎｉｎｔｈｅａｓｐｅｃｔｓｏｆｅｘｐｅｒｉｍｅｎｔｓ,ｔｈｅｏｒｉ…     

Observation of Single-slope Quasistatic Wings of Laser Induced Collision Energy Transfer

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｌａｓｅｒ ｉｎｄｕｃｅｄｃｏｌｌｉｓｉｏｎｅｎｅｒｇｙｔｒａｎｓｆｅｒ(ＬＩＣＥＴ)ｉｓａｎｏｐｔｉｃａｌｐｈｅｎｏｍｅｎｏｎｉｎｖｏｌｖｉｎｇｔｈｅｓｉｍｕｌｔａｎｅｏｕｓｉｎｔｅｒａｃｔｉｏｎｓｏｆｂｏｔｈｔｈｅｌａｓｅｒｆｉｅｌｄａｎｄｃｏｌｌｉｓｉｏｎ[1～ 3 ] .ＴｈｉｓＬＩＣＥＴｒｅａｃｔｉｏｎｃａｎｂｅｗｒｉｔｔｅｎａｓ:Ａ Ｂ ｈΩ →Ａ Ｂ (1)Ｄｕｒｉｎｇｔｈｅｃｏｌｌｉｓｉｏｎｏｆａｔｏｍ Ａｗｉｔｈａｔｏｍ Ｂ ,ａｔｏｍＡｇｏｅｓｂａｃｋｔｏｇｒ…     

Wavefront match simulation on receiver surfaces in coherent lidar

ＷａｖｅｆｒｏｎｔｍａｔｃｈｓｉｍｕｌａｔｉｏｎｏｎｒｅｃｅｉｖｅｒｓｕｒｆａｃｅｓｉｎｃｏｈｅｒｅｎｔｌｉｄａｒＺＨＡＯＹｕａｎＳＵＮＤｏｎｇｓｏｎｇＱＩＡＯＬｉｊｉｅＮＡＮＪｉｎｇｄａ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＰｈｙｓｉｃｓ，Ｈａ...     

A Novel OADM Based on Fiber Gratings

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｏｐｔｉｃａｌａｄｄ/ｄｒｏｐｍｕｌｔｉｐｌｅｘｅｒ (ＯＡＤＭ)ｉｓｔｈｅｋｅｙｃｏｍｐｏｎｅｎｔｏｆｏｐｔｉｃａｌｔｒａｎｓｐｏｒｔｎｅｔｗｏｒｋｓ(ＯＴＮ) .ＭａｎｙＯＡＤＭａｒｃｈｉｔｅｃｔｕｒｅｓｈａｖｅｂｅｅｎｒｅｐｏｒｔｅｄ ,ｓｕｃｈａｓｔｈｏｓｅｂａｓｅｄｏｎｗａｖｅｌｅｎｇｔｈｍｕｌｔｉｐｌｅｘｅｒｓ,ａｒｒａｙｅｄｗａｖｅｇｕｉｄｇｒａｔｉｎｇｓ(ＡＷＧ ) ,ａｃｏｕｓｔｏ ｏｐｔｉｃｔｕｎａｂｌｅｆｉｌｔｅｒｓ (ＡＯＴＦ) ,ｆｉｂｅｒＢｒａｇｇ ｇｒａｔｉ…     

杨振宁对称与物理

杨振宁对称与物理Ａｂｓｔｒａｃｔ：Ｔｈｅｃｏｎｃｅｐｔｏｆｓｙｍｅｔｒｙｉｎｐｈｙｓｉｃｓａｎｄｍａｔｈｅｍａｔｉｓｉｓｉｎｔｒｏｄｕｃｅｄｂａｓｅｄｏｎｔｈｅｃｏｍｍｏｎｉｄｅａａｂｏｕｔｓｙｍｍｅｔｒｙ．Ｉｔｉｓｓｈｏｗｎｔｈａｔｔｈｅｅｆｆｅｃ...     

NEOCLASSICAL TRANSPORT IN A TOKAMAK WITH ELECTRIC SHEAR

ＮＥＯＣＬＡＳＳＩＣＡＬＴＲＡＮＳＰＯＲＴＩＮＡＴＯＫＡＭＡＫＷＩＴＨＥＬＥＣＴＲＩＣＳＨＥＡＲＷＡＮＧＺｈｏｎｇ ｔｉａｎ1,ＧＬｅＣｌａｉｒ2(1.ＳｏｕｔｈｗｅｓｔｅｒｎＩｎｓｔｉｔｕｔｅｏｆＰｈｙｓｉｃｓ,Ｃｈｅｎｇｄｕ610041;2.ＣｅｎｔｅｒＣａｎａｄｉｅｎｄｅＦｕｓｉｏｎＭａｇｎｅｔｉｑｕｅ,Ｃａｎａｄａ)　　Ａｂｓｔｒａｃｔ:Ｎｅｏｃｌａｓｓｉｃａｌｔｒａｎｓｐｏｒｔｔｈｅｏｒｙｆｏｒａｔｏｋａｍａｋｉｎｔｈｅｐｒｅｓｅｎｃｅｏｆａｌａｒｇｅｒａｄｉａｌｅｌｅｃｔｒｉｃｆｉｅｌｄｗｉｔｈｓｈｅａ…     

Birefringence of (Al)GaAs/AlGaAs multiplequantum well optical waveguides

Ｂｉｒｅｆｒｉｎｇｅｎｃｅｏｆ（Ａｌ）ＧａＡｓ／ＡｌＧａＡｓｍｕｌｔｉｐｌｅｑｕａｎｔｕｍｗｅｌｌｏｐｔｉｃａｌｗａｖｅｇｕｉｄｅｓ￥ＭＡＣｈｕｎｓｈｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＥｌｅｃｔｒｏｎｉｃＥｎｇｉｎｅｅｒｉｎｇ，ＮａｔｉｏｎａｌＩｎｔｅ...     

Novel All Digital Scheme for Open Loop Fiber Optic Gyroscopes

ＮｏｖｅｌＡｌＤｉｇｉｔａｌＳｃｈｅｍｅｆｏｒＯｐｅｎＬｏｏｐＦｉｂｅｒＯｐｔｉｃＧｙｒｏｓｃｏｐｅｓＹＡＮＧＹｕａｎｈｏｎｇ（Ｔｈｅ５ｔｈＲｅｓｅａｒｃｈＤｉｖｉｓｉｏｎｏｆＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙｏｆＡｅｒｏｎａｕｔｓ＆Ａｓｔｒｏｎａｕ...     

Approximate Well Width Formulas of 1.55 μm Possible Compositional In_(1-x-y) Ga_yAl_xAs Strained Quantum-well Laser

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｉｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｔｈｅｒｅａｒｅｔｗｏｍａｉｎｍａｔｅｒｉａｌｓｙｓｔｅｍｓｆｏｒｌｏｎｇ ｗａｖｅｌｅｎｇｔｈｓｅｍｉｃｏｎｄｕｃｔｏｒｌａｓｅｒｓ.ＴｈｅＩｎ1 -ｘＧａｘＡｓ1 -ｙＰｙ ｓｙｓｔｅｍｈａｓｂｅｅｎｒｅｓｅａｒｃｈｅｄｅｘｔｅｎｓｉｖｅｌｙ[1 ,2 ] ,ｂｕｔｔｈｅＩｎ1 -ｘ-ｙＧａｙＡｌｘＡｓｓｙｓｔｅｍｏｎｌｙｒｅｃｅｎｔｌｙｂｅｇａｎｔｏｙｉｅｌｄｈｉｇｈｑｕａｌｉｔｙｒｅｓｕｌｔｓ[3,4] .ＦｏｒｔｈｅＩｎ1 -ｘ-ｙＧａｙＡｌｘＡｓｓｙｓ…     

金纳米粒子自组装薄膜的光谱学研究

采用柠檬酸钠还原氯金酸制备了金胶体，通过静电自组装制备了金纳米粒子薄膜，利用紫外-可见光吸收光谱等对金纳米粒子薄膜进行了光谱学研究，紫外-可见光吸收光谱表明所制备的金溶胶为单分散体系，根据自组装薄膜的X-射线衍射谱，由谢乐公式估算金纳米粒子的粒径约为21nm；X-射线光电子能谱显示氯金酸的还原反应比较完全，金主要以Au^0的价态存在，金胶体粒子通过静电吸引机制组装到PDDA改性的衬底表面；紫外-可见光吸收光谱和表面增强拉曼光谱显示，由于粒子间的电磁耦合，自组装金纳米粒子薄膜表现出协同等离子体共振吸收行为和表面增强拉曼散射效应。     

An acoustically enhanced gold film Raman sensor on a lithium niobate substrate

The surface enhanced Raman scattering effect has shown immense potential for detecting trace amounts of explosive vapor molecules. To date, efforts to produce a commercially available, reliable SERS sensor have been impeded by an inability to separate the electromagnetic enhancement produced by the metallic nanostructure from other signal enhancing effects. Here, we show a new Raman sensor that uses surface acoustic waves (SAWs) to produce controllable surface structures on gold films deposited on LiNbO₃ substrates that modulate the Raman signal of a target compound (thiophenol) adsorbed on the films. We demonstrate that this sensor can dynamically control the Raman signal simply by changing the SAW's amplitude, allowing the Raman signal enhancement factor to be directly measured with no variation in the concentration of the target compound. The physically adsorbed molecules can be removed from the sensor without physical cleaning or damage, making it possible to reuse it for real‐time Raman detection. Copyright © 2014 John Wiley & Sons, Ltd.     

An improved self‐assembly gold colloid film as surface‐enhanced Raman substrate for detection of trace‐level polycyclic aromatic hydrocarbons in aqueous solution

To detect trace‐level polycyclic aromatic hydrocarbons, some investigations of an improved self‐assembly method are carried out using gold colloid films for the preparation of the surface‐enhanced Raman scattering (SERS)‐active substrate. Extinction spectra and scanning electron microscopy images reveal that controllable surface plasmonic metal substrates can be obtained by increasing the temperature of (3‐aminopropyl)trimethoxysilane solution up to 64.5 °C. The SERS‐active substrates have a high enhancement factor, and they can be both easily prepared and reproducible. With the use of these substrates, different concentrations of pyrene and anthracene in aqueous solutions were detected by SERS. A further enhancement can be supported by shifted excitation Raman difference spectroscopy. Raman signals of pyrene and anthracene adsorbed on gold colloid substrates up to limits of detection at 5 and 1 nmol/l, respectively, can be obtained. The quantitative analysis shows the possibility of in situ detection of polycyclic aromatic hydrocarbons while such gold colloid film serves as a SERS‐active substrate. Copyright © 2012 John Wiley & Sons, Ltd.     

金纳米空心半球壳膜的可调谐光学性质研究

以单层聚苯乙烯微球阵列为模板,通过控制其表面金膜蒸镀时间,制备了具有不同厚度的空心半球壳结构的金纳米膜.利用扫描电子显微镜和自制光谱仪分别测量了金膜表面形貌和其透射光谱,并分析了金膜形貌与其光学性质间的关系,同时以4-巯基苯胺为探针分子测定了金膜的表面增强喇曼散射效应.结果表明,该金纳米膜的表面等离子体共振波长随膜厚度增大而发生红移,在可见与近红外波段较宽范围内可调谐,并且,当金膜共振波长与入射激发光波长较近时,探针分子可产生出较强的表面增强喇曼信号.同时,对该现象的产生机制也进行了理论解释.     

Multiscale electromagnetic SERS enhancement on self‐assembled micropatterned gold nanoparticle films

In this work, we demonstrate a cascaded, multiplicative electromagnetic enhancement effect in surface‐enhanced Raman scattering (SERS) on periodically micropatterned films made of colloidal gold nanoparticles, prepared by a self‐assembly approach, without implying lithography procedures. The multiplicative enhancement effect is obtained by combining surface plasmon near‐field enhancement due to nanoscale features with far‐field photonic coupling by periodic microscale features. The effect is observed for both internal Raman reporters (molecules attached to the Au colloids before their assembly) and external Raman probes (molecules adsorbed on the samples after film assembly). The ability of the patterned films for far‐field light coupling is supported by reflectivity spectra, which present minima/maxima in the visible spectral range. Finite‐difference time‐domain computer simulations of the electric field distribution also support this interpretation. The fabricated dual‐scale SERS substrates exhibit a good spot‐to‐spot reproducibility and time stability, as proved by the SERS response over a time scale longer than 1 month. The experimental demonstration of this cascaded electromagnetic enhancement effect contributes to a better understanding of SERS and can affect future design of SERS substrates. Moreover, such dual‐scale colloidal films prepared by convective self‐assembly can be of general interest for the broader field of nanoparticle‐based devices. Copyright © 2014 John Wiley & Sons, Ltd.     

碳化硅薄膜脉冲激光晶化特性研究

采用XeCl准分子激光对非晶碳化硅(a-SiC)薄膜的脉冲激光晶化特性进行了研究.通过原子力显微镜（AFM）和Raman光谱技术对退火前后薄膜样品的形貌、结构及物相特性进行了分析.结果表明，选用合适的激光能量采用激光退火技术能够实现a-SiC薄膜的纳米晶化.退火薄膜中的纳米颗粒大小随着激光能量密度的增加而增大；Raman谱分析结果显示了退火后的薄膜的晶态结构特性并给出了伴随退火过程存在的物相分凝现象.根据以上结果并结合激光退火特性，对a-SiC的脉冲激光晶化机理进行了讨论. 关键词： 激光退火 晶化 碳化硅     

Selective excitation of surface-enhanced secondary emission from biomolecules by substrates based on thin golden films

Thin (5–30 nm) golden films have been derived by vacuum deposition of gold onto dielectric substrates and subsequent annealing at temperatures of 200–350°C. These films allow selective detection of the desired component (fluorescence or Raman scattering) of the surface-enhanced secondary emission from the same resonantly driven molecule.     

Using surface enhanced Raman scattering to study vibrations of adsorbates on thin metallic overlayers on silver

We have studied the surface enhanced Raman scattering from molecules adsorbed on thin gold overlayers on silver island films. The Raman scattering of gold cyanide species adsorbed on gold overlayers decreases in intensity with gold overlayer thickness between 0.5 – 10 Å . This intensity decrease is consistent with a simple model which takes into account the damping of the electromagnetic resonances of the silver islands by the absorbing gold overlayer. Implications of these findings for the enhancement of Raman scattering from adsorbates on other metals deposited as overlayers on silver will be discussed.     

The role of direct surface interaction in surface enhanced Raman scattering by pyridine and CO on silver

The surface enhanced Raman scattering (SERS) phenomenon due to pyridine on silver and CO on silver in ultra-high vacuum (UHV) has been compared. The study was carried out for two different kinds of silver surfaces, island films and “cold” films on island films. We have reported earlier that it was necessary to warm the samples to about 70K in order to observe the full surface enhanced Raman spectrum when the pyridine was deposited on silver island films on sapphire substrates at liquid He temperatures. We call this the effect of a “low temperature anneal” and the present work indicates that this effect is more general than we originally thought. It has also been found that island films exhibit enhanced Raman scattering for pyridine but not for CO, although “cold” films enhance the Raman scattering of both CO and pyridine. This is the first clear indication that molecular specificity may be a part of the SERS phenomenon. The interpretation of these observations depends critically on our understanding of the SERS phenomenon.     

应用银溶胶膜探测水中抗生素的表面增强拉曼光谱研究

以自组装法制备的银溶胶膜为表面增强拉曼散射活性基底实现了对水中抗生素的痕量检测。采用微波加热法制备银溶胶,自组装法制备银溶胶膜。通过改变银溶胶的pH值及镀膜的次数,研究其对抗生素增强效果的影响。实验发现,采用不同pH值的银溶胶镀膜所获得的银溶胶膜的增强效果有很大差异,当银溶胶pH=4,且镀膜次数为五次时,增强效果最佳。以此银溶胶膜为基底对三种抗生素(氯霉素、环丙沙星、恩诺沙星)进行了SERS检测,可以检测到的最低浓度分别为120,15,120 nmol·L-1。结果表明,利用改进方法制备的银溶胶膜,可以对水中抗生素进行痕量检测,为实现养殖水中残留抗生素的检测提供了方法。