激光光斑测量系统的电路设计与实现

为了直接测量远场激光光斑,设计开发了一套基于热释电探测器阵列靶的激光光斑测量系统。针对热释电探测器噪声特性,将探测器响应信号通过前置放大、增益放大、峰值保持、A/D采集等电路处理,最后由主控计算机存储光斑信息,并对光斑图像进行分析处理。通过实际的远场激光测试实验,验证了该设计能够有效测量远场激光光斑。     

基于探测器阵列的激光远场光斑测量系统

设计开发了一套基于探测器阵列的激光远场光斑测量系统.在1.5 m×1.5 m的靶面尺寸上间隔10 cm排列了15行×15列激光探测器阵列,探测器响应信号经前置放大后分别进行同步脉冲产生和信号峰值保持、峰值信号A/D采样,最后经计算机通信存储,事后进行光斑图像的形成和分析处理.光斑能量密度测量范围10 μJ/cm~2～10 mJ/cm~2,单元探测器测量精度优于15%,最高测量激光频率可达500 Hz.可满足目前大功率激光干扰武器装备的测量需求.     

基于单片机的激光远场光斑直接测量系统

激光远场光斑测量对描述激光束的远场性能,评价激光器以及系统的实际工作性能具有重要意义,通过比较激光光斑远场直接测量与间接测量的优缺点,提出使用单片机控制的探测器阵列进行远场光斑直接测量．描述了系统结构,分析了关键技术,给出了主要程序的框图．该系统能够测量激光光斑大小、形状、总能量、能量分布、重心、束散角等参数,可适用于多种重复频率的激光器,测量面积大、精度高,实时性好,为激光束绝对空间能量分布的测量提供了有效手段。     

脉冲/连续高功率激光光斑分布阵列探测器

通过测量发射到远场的激光功率密度时空分布给出所需要的到靶总功率、光束质量、桶中功率、功率时间曲线等关键指标参数,是目前准确评价激光系统性能的重要技术手段。介绍了一种基于光电探测器阵列实现近红外脉冲激光功率密度时空分布的测量方法,可以实现900~1700 nm波长、动态范围大于2000倍的激光光斑参数测量。该阵列探测器具有测量面积大、单元一致性好、测量精度高等特点,并可同时实现脉冲和连续激光参数测试要求。给出了阵列探测器的总功率测量结果,测量值与激光器输出功率偏差在5%以内,且激光光斑分布测量结果准确可靠。该阵列探测器已在多套激光系统的参数测试中得到成功应用,可以作为响应波段内的脉冲/连续激光光斑参数测试一种有效技术方案。     

漫反射成像法的激光参数测量系统设计

精确地测量激光在大气传输后的光斑参数,是研究激光大气传播效应和分析激光发射系统性能的关键技术手段。测量激光远场参数的方法主要包括阵列探测法和相机成像法,目前在激光大气传输效应的测量评估中大都采用阵列探测法。由于探测器阵列靶受物理空间和研发成本等因素的限制不能均匀且高分辨率紧密排布,将造成采样光斑的失真,难以精确地测量远场光斑参数。针对此问题,利用相机分辨率高的特点,设计了一套基于漫反射屏成像法的激光参数测量系统。该系统最小测量分辨力小于0.39 mm,质心位置平均偏差为0.05 mm,测量光斑到靶功率不确定度优于10%。该系统能有效地测量激光发射系统的跟瞄精度和到靶功率,为分析激光大气传输效应和分析激光发射系统性能提供有效手段。     

复合式激光远场光斑分布定量测量技术研究

激光远场光斑分布测量是研究高功率激光大气传输效应的有效方法,同时也是评估强激光武器作战效能的重要手段。设计了一种基于摄像和阵列探测相结合的复合测量方法,实现了强激光远场光斑时空分布的定量测量。该系统可用于波长为(1064±10)nm、功率密度动态范围为2～5000 W/cm2激光的远场光斑分布测量。     

点阵式远场激光光斑监测系统的设计与实现

介绍了一种采用光电探测器点阵监测激光远场光斑的形状分布和激光脉冲时序的方法及其系统的实现。系统可实时监测光斑的形状和形心位置及激光脉冲的绝对时和相对时，激光脉冲发射时间测量精度优于0．2μs。在对激光目标指示器等远场激光照射器的性能评价和激光通信中的远场激光信息场的测量中有较大实用价值，并对大面积的激光光斑的测量有重要的参考价值。     

探测器阵列靶的激光光斑图像复原方法研究

为了准确地测量激光远场光斑参数,使得阵列探测法的研究逐渐成为热点。而阵列式靶板仪靶面探测器受空间物理限制和研发成本等因素影响均不能均匀紧密的排布,这将造成采样光斑失真。利用已知采样点参数对光斑图像实现高精度复原是利用阵列探测法测量光斑参数必须要解决的问题。因此,提出采用改进型的双三次插值算法对光斑图像进行复原。仿真分析并对比改进型双三次插值算法和其他插值算法,结果表明:运用改进型插值算法计算得到光斑总能量误差为1.7 %,光斑质心坐标偏移量在x轴方向和y轴方向较最邻近插值算法和双线性插值算法相比均能降低7.8 %和3.3 %,处理时间较双三次插值算法至少缩短35 %。该研究为提高阵列探测法测量远场光斑参数精度积累了一定的理论基础和实验数据。     

激光远场能量密度分布测试系统的实现

要设计了基于CCD成像法的激光远场能量密度测量系统,给出了CCD成像法测量远场激光能量密度分布的基本原理,并在特定条件下对激光能量测量模型进行简化.利用漫反射靶板将激光的能量分布信息采集至CCD相机,并在靶板的特征位置上安装能量探测器,依据激光能量模型,将激光光斑图像灰度信息与激光能量探头所测的实际能量值进行信息融合,...     

中红外高能激光光斑探测器

为定量测量中红外高能激光的总能量和功率密度时空分布,采用热吸收和光电量热复合相结合的测量方法,通过热吸收体温度场分布数值计算和探测器结构设计,研制了可用于长脉冲中红外高能激光测量的光斑探测器.探测器由量热堆、光电量热复合探测阵列、测温单元、数据采集单元和信号处理单元等儿部分组成.有效测量面积为12 cm×12 cm,光斑测量空间分辨率为2.4 cm,时间分辨率为25 Hz,总能最测晟不确定度小于10%,功率密度测量不确定度小于7%.实验表明,该探测器可测量最大能量超过50 kJ的数秒级脉冲中红外激光,采用该方法,可实现大面积、高能最和高空间分辨的高能激光光斑测量.     

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.     

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     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first