不同衬底温度生长的La_(0.5)Sr_(0.5)CoO_3薄膜椭圆偏振光谱研究

采用脉冲激光沉积法(PLD)在不同Si(100)衬底温度下制备了La_(0.5)Sr_(0.5)CoO_3(LSCO)导电金属氧化物薄膜.X射线衍射(XRD)分析表明,随着衬底温度升高LSCO薄膜的结晶质量增加,在650℃和700℃下制备的薄膜是具有单一钙钛矿结构的多晶薄膜.通过椭圆偏振光谱仪测量了400～1100nm波长范围内该导电金属氧化物薄膜的光学性质,采用双Lorentz振子色散关系及三相结构模型(Air/LSCO/Si)拟合获得了薄膜的光学常数.结果表明,薄膜的折射率随着衬底温度的升高而减小,然而在可见-近红外波长范围内消光系数随着衬底温度的升高而增大.这主要与薄膜的晶化质量和导电性能有密切的关系.     

Bi3．25La0．75Ti3O12超薄铁电薄膜的光学性质研究

采用化学溶液沉积法在Pt／Ti／SiO2／Si衬底上制备了厚度小于100nm的Bi3.25La0.75Ti3O12(BLT)铁电薄膜，测量了光子能量为2～4．5eV的紫外可见椭圆偏振光谱．根据经典的电介质光学色散关系和五相结构模型，拟合获得薄膜在透明区和吸收区的光学常数、表面粗糙度、薄膜与衬底界面层以及BLT薄膜的厚度．薄膜在透明区的折射率色散关系可以通过单电子Sellmeier模型成功地进行解释．最后，根据Tauc’s法则，得到Bi0.25La0.7Ti3O12薄膜的直接禁带宽度为3．96eV．     

B掺杂ZnO纳米薄膜的结构和光学特性研究

采用脉冲磁控溅射法制备了B掺杂ZnO(ZnO:B)纳米薄膜,并用X射线衍射(XRD)、扫描电子显微镜(SEM)和紫外-可见-近红外分光光度计分别研究了薄膜的结构和光学特性。结果表明:ZnO:B为多晶纳米薄膜,具有六方钎锌矿结构,且薄膜沿着c轴取向择优生长;在可见光和近红外光谱区的透光性能良好,其中在可见光区的平均透光率大于84%,而在近红外区的透光率随着波长增加而逐渐降低至45%。运用逐点无约束最优化法分析计算了薄膜的光学常数,在可见光区,ZnO:B纳米薄膜的光学常数随波长的变化很小且数值基本恒定,折射率约为2.0,而在紫外区,光学常数随波长的变化显著。     

多步旋涂CsPbBr3薄膜复光学常数的椭偏光谱研究

为了研究多步旋涂法制备的CsPbBr₃薄膜的光学常数，以溴化铅和溴化铯为原料，采用多步旋涂法在硅和FTO衬底上制得CsPbBr₃薄膜。利用光弹调制式椭偏光谱仪对硅衬底上的薄膜进行了椭偏光谱分析，使用Tanguy和Tauc-Lorentz 3组合模型对变角度的椭偏光谱进行参数拟合，得到了薄膜光学常数在1.00 eV～5.00 eV范围内的色散关系，并利用荧光发射光谱、吸收谱验证椭偏拟合结果。结果表明，多步旋涂法制备的CsPbBr₃薄膜的光学常数与其它方法相比具有一定的差异性，其中折射率可能与薄膜表面粗糙度呈负相关；椭偏拟合所得带隙为2.3 eV,验证了荧光光谱、吸收谱的计算结果。该研究为多步旋涂法制备的CsPbBr₃薄膜椭偏光谱拟合分析提供了参考。     

锑铋合金薄膜的光学常数

锑铋合金薄膜是一种新型超分辨光学功能材料,了解它的基本光学性质对其在光学信息存储及光子器件应用方面具有重要意义。用磁控溅射法制备了不同成分的锑铋合金薄膜(Sb1-XBiX,X=0,0.1,0.2,0.3,0.88,1),用椭圆偏振法测量了薄膜的光学常数(折射率n和消光系数k)。研究表明,在可见光波段(300～850nm),锑铋合金膜的折射率和消光系数都随着铋含量的增加而减小,且薄膜折射率和消光系数同时随波长的增加而增加,折射率呈现反常色散特性。用原子力显微镜、X射线衍射仪研究了成分变化对薄膜表面形貌和微结构的影响。研究表明,锑铋合金薄膜的微观结构呈现多晶态,晶化程度随着铋含量的增加而增加,这可能是影响其光学常数变化的主要因素。     

ZnO纳米结构薄膜的三阶非线性折射特性

采用直流溅射法在石英基片上制备了ZnO纳米结构薄膜。X射线衍射(XRD)谱表明ZnO尺寸约为5nm。利用Z 扫描技术,以锁模Nd:YAG激光器作光源(脉宽35ps,波长为355nm),在共振区域测定了ZnO纳米薄膜的三阶非线性光学常数,其非线性光学折射率常数n2=-5.7×10-8esu。     

衬底温度对氧化钛薄膜的光学常数影响

采用沈阳CK-3高真空磁控溅射薄膜沉积设备在K9玻璃衬底上分别制备了衬底温度为150℃、200℃和250℃的氧化钛薄膜。XRD分析显示这三种温度制备的薄膜由于制备温度不高均没有明显衍射峰,为非晶薄膜。薄膜的光学常数由德国SENTECH SE 850型光谱型椭偏仪对薄膜测试得到,测试波长为300 nm～800 nm,采用Cauchy模型对测试结果进行拟合。结果发现随着制备衬底温度的增大,薄膜的折射率n和消光系数k都随着增大。在衬底温度从150℃增大到250℃时,薄膜的光学带隙从3.46 eV减小到3.02 eV。     

非晶硅碳（a-SiC∶H）薄膜光学常数的透射谱表征

报道了一种用透射谱数据分析法计算非晶硅碳薄膜的厚度、折射率、吸收系数和光学带隙等光学常数的方法和程序．这一方法引用有效谐振子模型理论的折射率色散关系，所有公式均为解析表达式，便于进行数据处理，无须专用软件，使用Excel即可完成，适用于多种半导体薄膜材料．将这种方法应用于PECVD方法制备的非晶硅碳（a-SiC∶H）薄膜，对其光学特性进行了分析．     

溶胶—凝胶工艺制备梯度折射率薄膜的研究

采用溶胶－凝胶工艺制备梯度折射率薄膜，薄膜中的折射率变化是由折射率调制元素在湿凝胶中的化学反应和扩散产生。本文详述了材料的制备过程，并对材料的结构和光学性能进行了研究。     

尖晶石结构LiTi2O4薄膜光学性质研究

用激光脉冲沉积(PLD)方法,以MgAl_2O_4(001)为衬底制备了过渡金属氧化物LiTi_2O_4薄膜.采用X射线衍射(XRD)对所制备材料进行结构测试,结果表明,材料具有立方尖晶石单相结构,结晶性能良好.应用拉曼光谱和光谱椭偏仪(SE)分别研究了材料在常温下的拉曼活性声子特性和可见-近红外波段的折射率和消光系数.应用第一性原理计算了LiTi_2O_4材料的能带结构和态密度,结果表明理论计算结果和实验测试结果具有很好的一致性,能带计算结果能够很好的解释薄膜的光学常数.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks