夹角式强度反射型光纤声传感器

介绍了一种基于反射式强度型光纤传感原理的光纤声传感器,该传感器通过光纤模块将发射光纤和接收光纤的夹角固定为60°,同时采用基于微加工技术制作的反射振动膜片敏感声音信号并调制光信号强度.建立了该传感器的理论模型,并通过仿真和实验分析得到系统的最佳工作距离为8 μm,灵敏度为2.49 μW/μm.实验测试结果表明,该声传感器样机对声音的探测灵敏度为30 mV/Pa,同时给出了样机的频率响应及线性度测试结果.     

MEMS矢量传声器研究进展

矢量传声器由声压传感器和质点振速传感器复合构成,可时间同步、空间共点测量声场声压标量及质点振速矢量信息,在开展振动噪声监测、被动声测定位以及声全息成像等相关声学测试方面有着独特的优势,因而具有重要的工程应用价值.质点振速传感器是矢量传声器的核心部件,具有偶极子指向性,可直接感测声场质点振速各正交分量.基于此,介绍基于微机电系统(Micro-Electro-Mechanical System,MEMS)技术的矢量传声器的研究进展,概述MEMS矢量传声器的工作原理、设计制作及工程应用等方面的发展现状.     

MEMS压电指向性传声器仿真与性能优化

为提高微机电系统(MEMS)压电指向性传声器的声压灵敏度,该文采用有限元法对一种MEMS压电指向性传声器进行了仿真与性能优化。对于该压电指向性传声器结构的声压灵敏度随压电层材料种类、厚度及长度的变化进行了研究,优化了结构参数,提高了器件的灵敏度及信噪比。结果表明,当硅梁厚为10 μm,压电层厚为6.3 μm时,器件灵敏度达到最大,较先前结构提高了约14 dB。     

压电致动微雾化器的压电-固-液耦合特性分析

针对微雾化器存在的多能域能量耦合问题,建立了压电微雾化器的固-液-声耦合模型,对其耦合特性进行了数值计算,并着重分析了液体层厚度对耦合性的影响,得到了液体层厚度对系统的结构振动、声压力波特性的影响规律.结果表明,由于液体层与固体的耦合作用,压电振子振动的同时,喷孔膜也产生振动,并且两者间存在相位关系;液体层的厚度直接影响结构的耦合性、谐振频率大小及背膜与喷孔膜的相位差,并且存在最佳的设计参数,当液体层厚度为500 μm时,谐振频率最大约是38 kHz,此时,可产生较大的声压力波及较大的流量.微雾化器设计时只考虑压电振子的振幅是不全面的,必须同时考虑喷孔膜的振动及与背膜的相位关系,新的设计原则可为微雾化器的优化设计提供指导依据.     

振动环境下微小间隙的光栅测量法

为测量振动环境下层间结构内部微小间隙的相对变化,设计了一种用于狭小空间内的平直光栅传感器。根据指定应用条件研究设计光栅传感基片的封装方案及其主要技术指标,并制作出平直光栅传感器。该传感器测量范围0.5 mm~0.8 mm,标定指标良好。通过试验应用证明,采用光栅传感器可实现振动环境下微小间隙的直接测量,且不用破坏原结构,与传统方法相比,数据真实可信,满足测量精确度μm量级要求。     

一种屏蔽式电涡流传感器的研制

某构件为多层窄间隙结构的容器装置,为测试在具有一定压力的高速流场中流体诱发的内层板振动情况,基于电涡流原理设计了一种屏蔽式电涡流传感器,完成了屏蔽式电涡流传感器的探头线圈参数和探头壳体结构参数的优化设计、装配调试和第三方校准。试验结果表明:研制的屏蔽式电涡流传感器,在不干扰"流场",对装置结构不构成影响的前提下,实现了板间窄间隙振动的测试,传感器可靠有效。     

CMOS集成硅流量传感器

本文介绍了一种流量传感器新的工作原理:当流体流过加热的芯片时,为保持芯片温度恒定所需功耗的改变,可以用来作为流体速度的量度。本文用CMOS工艺首次实现了这种原理的集成流量传感器。该传感器结构简单、尺寸小(1×1.9mm),灵敏度高(在芯片温度55℃、流体温度30℃、流速50cm/s时,输出达80mW)。     

一种用于管道地面标记的MEMS仿生矢量声传感器

随着管道越埋越深,基于声检测原理的地面标记是现今管道技术的发展趋势.针对目前对管道内检测器标记难的现状,首次提出一种高灵敏度、高信噪比、高分辨率的新型MEMS仿生矢量声传感器运用到地面标记系统中.该文将该传感器与目前广泛应用在地面标记系统中的压电陶瓷振动传感器和动圈式高灵敏度地震检波器进行了不同的模拟对比实验.实验结果表明,MEMS仿生矢量声传感器具有检测距离长,可靠性能好,对土壤环境要求低等优点,从而验证了MEMS仿生矢量声传感器检测微弱信号的可行性和其在标记定位管道内检测器方向的良好的应用前景.     

基于矢量语音传感器的双麦克风语音增强算法

在语音增强技术领域,双麦克风语音增强技术具有尺寸小、功耗低的优势,因此得到了越来越多的应用。传统的双麦克风语音增强技术一般使用全向麦克风进行信号采集。矢量语音传感器可以采集声矢量信息,其“8”字形指向性使其天然具有抑制环境噪声的能力。将基于相干函数的双麦克风语音增强算法与矢量语音传感器相结合,提出一种基于矢量语音传感器的双麦克风语音增强算法,对其指向性进行仿真分析,并在消声室进行实测验证。结果表明,与相同阵列形式下的全向麦克风双麦阵列相比,矢量语音传感器双麦阵列具有更好的指向性和语音增强效果。     

基于磨砂玻璃压印的压阻式柔性压力传感器

柔性压阻传感器结构简单、电阻变化范围宽、灵敏度高,在电子皮肤和医疗健康检测等领域受到广泛的关注和研究.使用不同目数的磨砂玻璃作为模具制备了具有微结构的多壁碳纳米管(MWCNT)/聚二甲基硅氧烷(PDMS)导电复合材料,并实现了微结构柔性压阻传感器.研究表明,目数最小(微结构尺寸为125 μm)的磨砂玻璃制备的传感器具有...     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.