GaAs／AlxGa1—xAs和AlxGa1—xAs／AlAs超晶格的喇曼散射对比研究

报道不同层厚的ＡｌＡｓ／ＡｌｘＧａ１－ｘＡｓ及ＧａＡｓ／ＡｌｘＧａ１－ｘＡｓ短周期超晶格的纵光学声子模的室温喇曼散射测量结果．在非共振条件下,观察到ＡｌＡｓ／ＡｌｘＧａ１－ｘＡｓ中限制在ＡｌｘＧａ１－ｘＡｓ混晶层中的类ＧａＡｓＬＯ限制模和限制在ＡｌＡｓ层中的ＡｌＡｓＬＯ限制模,还观察到ＧａＡｓ／ＡｌｘＧａ１－ｘＡｓ中限制在ＡｌｘＧａ１－ｘＡｓ混晶层中的类ＡｌＡｓＬＯ限制模和限制在ＧａＡｓ层中的ＧａＡｓＬＯ限制模．在近共振条件下,还观察到了ＡｌＡｓ／ＡｌｘＧａ１－ｘＡｓ中ＡｌＡｓ的界面模．根据线性链模型,把测量的ＬＯ限制模的频率按照ｑ＝ｍｎ＋１２πα０展开,给出了ＡｌｘＧａ１－ｘＡｓ混晶的类ＡｌＡｓ支和类ＧａＡｓ支光学声子色散曲线．     

静压下ZnS0.02Te0.98混晶的共振喇曼散射研究

在１５Ｋ和１～３ＧＰａ静压范围内研究了ＺｎＳ０．０２Ｔｅ０．９８混晶的共振喇曼散射，样品用ＭＢＥ方法生长在（００１）晶向的半绝缘ＧａＡｓ衬底上，利用静压调制带隙实现也４８８．０ｎｍ线的共振喇曼散射，观察到类ＺｎＴｅ和类ＺｎＳ两类ＬＯ声子模以及它们的倍频模和组合模－测得类ＺｎＴｅ的ＬＯ声子模的压力系数为４．５ｃｍ＾－１／ＧＰａ。     

InAsP/InGaAsP量子阱的子带跃迁计算

采用有效质量框架下一维有限深单阱的Ｋｒｏｎｉｇ － Ｐｅｎｅｙ 模型对ＩｎＡｓｙＰ１ － ｙ／Ｉｎ１ － ｘＧａｘＡｓｙＰ１ － ｙ 量子阱结构的跃迁波长与组分及阱宽间的关系进行了计算,并采用能量平衡模型计算了此材料体系的生长临界厚度。计算结果表明,ＩｎＡｓｙＰ１ － ｙ／Ｉｎ１ － ｘ ＧａｘＡｓｙＰ１ － ｙ 是制作１ ．３ μｍ 或１ ．５５ μｍ 波长量子阱激光器的良好材料体系,此材料体系在２ ～３ μｍ 的中红外波段也有很大潜力。采用ｙ 约为０ ．４ 的组分和约１ ．３ ％ 的压应变可以满足１ ．３ μｍ 波长激光器的要求, 而ｙ 约为０ ．５５ 的组分和约１ ．８ ％ 的压应变可以满足１ ．５５ μｍ 波长激光器的要求。     

InxGa1—xAs／AlyGa1—yAs多量子阱的高压光致发光研究

用金刚石对顶砧压力装置在浓氮温度下和０～４ＧＰａ的压力范围内测量了不同阱宽（１．７～１１．０ｎｍ）的ＩｎｘＧａ１－ｘＡｓ／ＡｌｙＧａ１－ｙＡｓ（ｘ，ｙ＝０．１５，０；０．１５，０．３３；０，０．３３）多量子阱的静压光致发光谱，发现在Ｉｎ０．１５Ｇａ０．８５Ａｓ／ＧａＡｓ多量子阱中导带第一子带到重空穴第一子带间激子跃迁产生的光致发光峰能量的压力系数随阱宽的增加而减小，在Ｉｎ０．１５Ｇａ０．８５Ａｓ／     

［（Cdse）_m（ZnSe）_n］_p－Znse多量子阱中的多声子散射

对用原子层外延方法，在［００１］晶向ＧａＡｓ衬底上生长的［（Ｃｄｓｅ）ｍ（Ｚｎｓｅ）ｎ］ｐ－ＺｎＳｅ应变量子阱结构，在１０～３００Ｋ温度范围内测量了喇曼散射光谱，观察到两种类ＺｎＳｅＬＯ声子限制模．利用改变样品温度和入射光能量实现了共振喇曼散射，观察到高达７阶的类ＺｎＳｅＬＯ声子模．并讨论了多声子喇曼散射和热萤光过程的区别．     

（n11）面上生长的Ⅲ—Ⅴ族半导体的喇曼散射研究

报道不同指数面（ｎ１１）上生长的Ｇａ０．５Ａｌ０．５Ａｓ 和Ｉｎ０．５２Ａｌ０．４８Ａｓ系列样品的长光学声子模的室温喇曼散射测量结果．在背散射条件下不同的偏振配置下,观测到这些样品中对应的Ｌ０ 模和Ｔ０ 模的相对强度随着不同的指数面呈现出规律变化,同时把这一实验结果与（ｎ１１）指数面上生长的闪锌矿结构材料的喇曼散射选择定则的理论预计相比较,实验结果与理论预期的一致     

InGaAsP及其量子阱结构的LP－MOCVD

报道了用低压金属有机化学汽相淀积（ＬＰ－ＭＯＣＶＤ）技术在（１００）ＩｎＰ衬底上生长ＩｎＧａＡｓＰ体材料及ＩｎＧａＡｓＰ（１．３μｍ）／ＩｎＧａＡｓＰ（１．６μｍ）量子阱结构的生长条件和实验结果。比较了５５０℃和５８０℃两个生长温度下Ｉｎ１－ｘＧａｘＡｓｙＰ１－ｙ体材料及相应量子阱结构的特性，表明在５８０℃生长条件下，晶体具有更好的质量和特性。     

InP与In1—xGaxAsyP1—y／InP的电解液电调制反射光谱

研究了ＩｎＰ样品和Ｉｎ１－ｘＧａｘＡｓｙＰ１－ｙ液相外延片在３００～８００ｎｍ范围内的电调制反射光谱，利用Ａｐｓｎｅｓ三点法计算了临界点能量，增宽因子和自旋轨道分裂值。通过实验曲线与理论公式的拟合，确定了临界点能维数及相位因子，并且间接提供了被测Ｉｎ１－ｘＧａｘＡｓｙＰ１－ｙ四元合金的组份值及其它临界能量值Ｅ０和Ｅ２。     

3～5.3μmIn_xGa_(1-x)As/Al_yGa_(1-y)As/Al_zGa_(1-z)As非对称台阶量子阱红外探测器

本文报道我们率先研制出的３～５．３μｍＩｎｘＧａ１－ｘＡｓ／ＡｌｙＧａ１－ｙＡｓ／ＡｌｚＧａ１－ｚＡｓ非对称台阶量子阱红外探测器的制备和性能．该探测器具有光伏特征，７７Ｋ温度、±７Ｖ外偏压下的５００Ｋ黑体探测率达到约１．０×１０１０ｃｍ·Ｈｚ１／２／Ｗ，并且，与１→２子带间跃迁相对应的光电流峰值响应波长可随外偏压在中红外（３～５．３μｍ）波段作适当调谐．运用平面波展开法，依据样品的阱、垒结构参数，计算了ＩｎｘＧａ１－ｘＡｓ／ＡｌｙＧａ１－ｙＡｓ／ＡｌｚＧａ１－ｚＡｓ非对称台阶量子阱１→２子带间跃迁的Ｓｔａ     

MOCVD生长GaN的喇曼散射谱

对在ＧａＡｓ（００１）、Ａｌ２Ｏ３（０００１）和Ｓｉ（１１１）等衬底上ＭＯＣＶＤ技术生长的ＧａＮ薄膜进行了背散射几何配置下的喇曼散射测试分析和比较，观察到了α相ＧａＮ的Ａ１（ＬＯ）模、Ａ１（ＴＯ）模、Ｅ１（ＬＯ）模和Ｅ２模．结合Ｘ射线衍射谱，分析了因不同生长工艺导致ＧａＮ／ＧａＡｓ样品的不同结构相的喇曼谱的差异，发现ＧａＮ的喇曼谱与ＧａＮ外延层的结构相、完整性及工艺条件有关，可利用其作为检测ＧａＮ外延层结构特性的一种有用手段．对含有少量β相ＧａＮ样品，观测到了包含有β相ＧａＮ贡献的声子模式（７４０ｃｍ－１）．     

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