自聚焦共焦式微型探测系统的研究

为解决微小内轮廊为代表的微小尺寸的非接触测量问题，本文提出了将自聚焦透镜体积小与共焦显微技术的纵向层析特性有机结合的自聚焦共焦微型显微技术的光聚焦探测系统。介绍了系统的工作原理和结构装置，对系统中的关键技术进行了优化设计，通过对自聚焦透镜、针孔，光源及探测器系统的设计，可以有效地实现高精度微型光聚焦探测，初步实验结果表明，系统的轴向分辨率可达10nm。     

连续太赫兹反射式共焦扫描显微成像特性分析

太赫兹反射式共焦扫描显微成像系统分辨率较高且可呈现物体三维像,因此具有很大的应用价值。针对一种连续太赫兹反射式共焦扫描显微成像实验光路,在所确定的系统参数条件下,计算分析了两种太赫兹波长(118.83μm和184.31μm)的系统轴向响应特性。仿真结果表明,所设计的波长118.83μm的成像实验装置横向分辨率可达0.23 mm,轴向分辨率约为4.27 mm;波长184.31μm的系统横向分辨率可达0.36 mm,轴向分辨率约为6.63 mm。探测器轴向偏移影响大于横向偏移影响。     

具有高空间分辨力的双极性绝对式差动共焦检测方法

提出一种用于超精密三维微细结构测量的横向光学超分辨、轴向纳米级分辨的绝对式高空间分辨力共焦检测方法,该方法利用超分辨光瞳滤波技术最大程度地改善共焦显微系统的横向分辨力,利用探测器轴向偏置的双探测共焦光路布置和双探测信号归一化差动接受最大程度地改善共焦显微系统的轴向分辨力,最终实现共焦检测系统的高空间分辨力双极性绝对测量.文中以整形环形光横向超分辨为例,初步验证了提出的高空间分辨力差动共焦扫描检测方法的有效性.实验表明:当入射激光束波长λ=632.8nm,测量物镜数值孔径取NA=0.85,ε=0.5,μM=6.95时,整形环形光瞳式差动共焦传感器的横向分辨力优于0.2μm,轴向分辨力优于2nm.     

基于小孔阵列的并行激光共焦显微检测技术研究

为了对微纳加工工件进行三维形貌测量,建立了 基于小孔阵列的并行激光共聚焦显微检测系统。利用自行研发的三波长皮秒脉冲激光 加工机在面积为1cm²的铜箔上制备100×100的小孔阵列,以实现 并行分光,小孔的平 均直径为43.6μm,间距为100μm。利用小 孔阵列系统,分别对镀 膜平板和螺钉进行了三维测量。实验结果表明,在轴向平移台步距为1μm的条件下,本文 系统能对待测样品 实现轴向分辨率为1μm、横向分辨率为20μm的三维扫描并重构出 样品形貌。本文共焦显微检测方法能大大提 高共焦扫描速度,能很好满足一般工业检测需求,本文为并行共焦探测技术提供了一条新 的研究和运用方法。     

阵列式共焦显微系统超分辨特性的研究

针对光学阵列共焦显微系统中存在分辨力的下降，提出引入一种新型三区振幅型光瞳滤波器以提高其三维探测能力。首先根据基尔霍夫衍射理论推导出光学阵列共焦显微系统三维相干成像公式，与现有理论相比，能更准确地定量描述共焦阵列成像过程，进而将共焦阵列显微技术和光学超分辨技术有机结合，利用三维超分辨评价函数对光瞳滤波器的参数进行优化设计，通过压缩各探测光路的横向和轴向半极值宽（HWHM），以提高其三维扫描探测能力，从而为实现快速、超精密三维测量提供了一种有效的技术途径。     

自聚焦共焦探测系统轴向分辨率的影响因素

从微小内尺度测量角度出发，研究了针孔尺寸、探测器位置、透镜的数值孔径、放大倍率和杂散光等对自聚焦共焦式探测系统轴向分辨率的影响。结果表明，为提高系统的轴向分辨率，需将有效针孔尺寸控制在≤2.5；探测器需配以精密微调整装置以实现横向精确定位；选用差动共焦光路及大数值孔径和大放大倍率的自聚焦透镜，同时，偏振光路的使用将有效的提高系统的信噪比。     

光纤共焦扫描显微图像渐晕校正的研究

光纤共焦扫描显微镜是一种使用单模光纤代替传统共焦扫描显微镜的针孔来形成点光源与点探测器的激光共焦扫描显微系统。本文在详细地分析了光纤共焦扫描显微镜的双振镜扫描系统产生渐晕原因的基础上,给出了渐晕校正的详细算法,并设计了与扫描采集集成为一体的硬件校正系统。     

变迹术对改善共焦系统分辨率的实验研究

给出了在反射式光纤共焦扫描成像系统中 ,利用变迹术提高系统分辨率的原理 ,并做了相应的对比实验 .在加入变迹掩模后 ,系统对物体的成像响应曲线、物体直边边缘展宽量都有所改善 .实验数据证明 ,改变光瞳函数可以提高系统的横向分辨率 ,同时不降低系统的纵向分辨率 .     

一种新型VLSI电路外部电光探测器北大核心CSCD

采用极化聚合物电光材料,设计制作出一种结构新颖的亚微米VLSI电路正面入射式外部电光探测器。通过在探测器中引入参考电极,实现了电压的标定测量;利用1μm线宽指状电极的电场分布,验证了触立式极化聚合物电光探测器对电场具有较高的空间分辨率。实验证明,该新型外部电光探测器的空间分辨率可达0.5μm,完全满足亚微米电路无损探测的要求。     

共焦扫描显像成像系统的非相干光学传递函数

共焦扫描光学显微（ＣＳＯＭ）系统有透射式和反射式,相干光和非相干光荧光等类型。ＣＳＯＭ系统的平面分辨率和纵发辨率依赖于放置在光电探测器前面的空间滤波器的孔径大小。根据不同孔径计算反射式荧光ＣＳＯＭ系统的非相干光学传递函数,并进一步说明反射式荧光ＣＳＯＭ系统的成像特性对孔径的依赖关系。     

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.     

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.     

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