用于挥发性气体检测的声表面波器件的环境特性研究

声表面波在气敏应用中具有快速、高灵敏、微型、轻质的独特优势,因而在单兵防化、公共安全及工业流程监控等领域极具应用前景。中国科学院声学研究所王文团队与军事科学院防化研究院潘勇团队在长期声表面波气敏机理与器件优化研究的基础上,为推进声表面波气敏技术的实用化进程,持续开展了声表面波气敏器件及系统环境适应性的研究。     

磁控溅射制备ZnO薄膜及其声表面波特性

通过射频磁控溅射技术在GaAs，Au/GaAs，Si和玻璃基片上成功制备了ZnO多晶薄膜，利用X射线衍射对ZnO薄膜的取向、结晶性进行了表征，结果表明ZnO薄膜呈完全c轴取向，Au缓冲层可以有效地改善ZnO薄膜的晶体质量，X射线摇摆曲线结果表明ZnO(002)衍射峰的半高宽仅为2.41°，同时发现Au缓冲层的结晶质量对ZnO薄膜的c轴取向度有很大影响，通过扫描电子显微镜对ZnO/GaAs和ZnO/Au/GaAs薄膜的表面形貌进行了观测，利用网络分析仪对IDT/ZnO/GaAs薄膜的声表面波特性进行了测量. 关键词： ZnO薄膜 X射线衍射 声表面波     

我国声表面波研究与发展

本文综述了我国声表面波研究简要发展历程及现状,指出了今后我国声表面波研究发展的重点。     

亚磷酸铝中温度补偿取向的声表面波特性研究

美国Allied公司(AC)对该公司生长的高质量亚磷酸铝(AlPO_4)单晶的五种切割测量了声表面波速度(v)、电声耦合系数(△v/v)和频率/温度特性(△f/f).理论预测的五种切割取向为:三种单转动切割——球体x轴80.4°、柱体x轴18.5°和x切19.1°;两种双转动切割——双转动A切和双转动B切.取向对应的欧拉角见表Ⅰ.     

全国声表面波工艺与材料学术讨论会

一九八一年十二月二十六日至三十日由中国电子学会应用声学学会主持,压电与声光技术研究所和四川大学共同组织的全国声表面波工艺与材料学术讨论会在重庆召开.出席这次会议的单位四十二个,正式代表五十六人,列席代表三十人,会上宣读了二十九篇论文报告.会议还特邀了钱振型高级工程师作了有关“日本声表面波技术概况”的考察报告.     

声表面波器件变频快速模拟方法

声表面波器件的级联有限元模拟方法是从整体结构中分离出若干独立的基本单元,通过基本单元边界矩阵的级联实现有限长器件结构的模拟.在实际设计中,通过优化叉指换能器的指条周期,激发出不同波长的声表面波,调整声表面波器件的谐振频率,这导致级联有限元模拟方法存在频繁的单元建模与数据传输过程.为提高模拟效率,该文提出了一种波长(频率...     

声表面波延迟线控制的调频振荡器

本文对有关声表面波调频振荡器的基础和理论作了短评,给出了一个采用ST切石英的300兆赫声表面波调频振荡器在±200kHz左右范围内调频的实验结果.其特点是能将大的频率调制偏移与可能达到的较高的频率稳定性结合起来,同时减少了输出信号的谐波成分.它的性能介于LC和晶体振荡器之间.     

声表面波石英温度计

据报道,声表面波器件可用以构成温度传感器. 这种温度传感器的原理如下:如果选择合适的基体材料,在其表面制作声表面波延迟线并与外部放大器组成声表面波振荡器,将延迟线部份密封,即构成一种对温度场很敏感的新型温度传感器,当温度改变时即引起振荡频率的偏移.可见,正确选择基休材料是至关重要的.文献报道JCL和LST两种切割     

Interaction of a Surface Acoustic Wave with a Two-dimensional Electron Gas

When a surface acoustic wave (SAW) propagates on the surface of a GaAs semiconductor, coupling between electrons in the two-dimensional electron gas beneath the interface and the elastic host crystal through piezoelectric interaction will attenuate the SAW. The coupling coefficient is calculated for the SAW propagating along an arbitrary direction. It is found that the coupling strength is strongly dependent on the propagating direction. When the SAW propagates along the [011] direction, the coupling becomes quite weak.     

Interaction of a Surface Acoustic Wave with a Two-dimensional Electron Gas

When a surface acoustic wave （SAW） propagates on the surface of a GaAs semiconductor, coupling between electrons in the two-dimensional electron gas beneath the interface and the elastic host crystal through piezoelectric interaction will attenuate the SAW. The coupling coemcient is ~alculated for the SAW propagating along an arbitrary direction. It is found that the coupling strength is strongly dependent on the propagating direction. When the SAW propagates along the [011] direction, the coupling becomes quite weak.     

表面波布拉格声光互作用耦合波方程的研究

定义了压电晶体的增劲声光系数,它反映压电晶体中声光、电光和压电效应共同作用的结果。从参量互作用基本理论出发,同时考虑声光效应、电光效应和压电效应三个因素,用一个压电增劲声光系数来表示三种因素的共同作用,导出表面波声光布拉格互作用的耦合波方程。并求解得出相应衍射效率的计算公式。该式说明在弱声光互作用条件下,衍射导光波强度与超声功率成正比。表面波声光器件具有体积小、工作稳定、能耗小、易于集成等优点。可以用作光偏转器、光调制器、滤光器。在光通信以及各类实时信号处理,如相关、卷积、频谱分析、矩阵光计算等领域具有广泛的应用前景。     

利用表面波对激光的衍射效应测水波频率和波速

利用液体表面波（surfaceacousticwaves,SAW）对激光的衍射效应,建立起一种新的低频液体表面波频率的光学测量方法;同时对表面波的传播速度进行了测量,拟合数据对波速和波长之间的关系进行了研究。     

Visualization of 50 MHz Surface Acoustic Wave Propagation Using Stroboscopic Phase-Shift Interferometry

A Stroboscopic phase-shift interferometry has been developed to visualize surface acoustic wave (SAW) propagation on SAW devices quantitatively. The developed interferometry is a Fizeau-type one with a multi-mode semiconductor laser diode and an optical isolator. With the laser light illuminating stroboscopically, observed interference intensity gives information about average displacements of the vibrations. Fifty MHz SAW propagation on the surface of the SAW device has been measured with the interferometry. Distribution of the SAW along the propagation path has been observed, whose amplitude is 3 nm (p-p). Repetition accuracy evaluated with the root mean square method is 1/2500 of the laser wavelength. The system is useful for estimating and improving performances of micro-devices.Presented at 1996 International Workshop on Interferometry (IWI ‘96), August 27-29, Saitama, Japan.     

水下低频声信号的激光探测及波的衰减

为了探测几十赫兹的低频水下声信号,建立了水下低频声信号的光学探测系统,得到了稳定、清晰的衍射图样.得到了衍射图样的宽度与声源距离的变化关系,声源距离越小,衍射图样越宽.当水下声波传至水表面后,实验上得到了表面声波的衰减特性,理论上得到了衍射图样的角宽度和液体表面波振幅的解析关系式.发现表面波振幅的衰减随距离是指数型衰减.并研究了衰减系数随频率的变化,频率不同衰减系数也不同,而且频率越大,衰减系数越小.     

Two-Dimensionally Self-Holding Deflection Mirror Using Surface Acoustic Wave Motor

We have developed a two-dimensionally deflecting mirror actuating system with a deflection angle of 20°, which takes full advantage of the characteristics of a two-dimensional surface acoustic wave (SAW) motor. A magnetic slider moves with frictional drive by the Rayleigh mode of the SAW and deflects the mirror by the force of magnetic attraction. For the actuation of a 20° deflection angle, only a 10 ms duration of driving voltage is required owing to the high-speed characteristic of the motor, followed by an additional 10 ms for damping of the mirror structure produced in order to complete holding of the angle. No power supply is necessary to hold the angle. Furthermore, the resolution of the angle is 0.0015° because of the high-resolution capability of the motor. The mirror deflection system showed a 10⁴ dynamic range of angle positioning ability.     

单根电极或沟槽形成的栅格对声表面波的散射*

该文借鉴汪承灏先生研究栅格声表面波散射的技术路线,提出一种既不限制基片和栅格形状、类型,也不限制声波入射方向,可精确计算栅格对SAW散射的有限元通用模型。作为对《超声学》第六章"声表面波"中栅格对声表面波的反射和体波散射一节部分结论的进一步阐释和说明,计算了YZ-Li Nb O3和128?YX-Li Nb O3单晶上厚度为200 nm、宽度为1μm的单根悬浮铝栅条以及沟槽在不同频率下的反射系数曲线。提出的计算方法今后可推广应用于层状结构基底、应用到非规则指条、沟槽、金属点阵、基片端面、台阶等的反射的精确分析,为优化设计新型声表面波器件奠定理论基础。     

激光等离子体的声学诊断研究

提出了利用激光等离子体声波对高功率激光与材料相互作用过程进行了诊断的方法。实际测量了波长０．５３μｍ激光与几种金属材料相互作用的过程，其结果与采用春它方法得到的结果基本吻合。     

Study on the electromechanical coupling coefficient of Rayleigh-type surface acoustic waves in semi-infinite piezoelectrics/non-piezoelectrics superlattices

The electromechanical coupling coefficient of Rayleigh-type surface acoustic waves in semi-infinite piezoelectrics/non-piezoelectrics superlattices is investigated by the transfer matrix method. Research results show the high electromechanical coupling coefficient can be obtained in these systems. The optimization design of it is also discussed fully. It is significantly influenced by electrical boundary conditions on interfaces, thickness ratios of piezoelectric and non-piezoelectric layers, and material parameters (such as velocities of pure longitudinal and transversal bulk waves in non-piezoelectric layers). In order to obtain higher electromechanical coupling coefficient, shorted interfaces, non-piezoelectric materials with large velocities of longitudinal and transversal bulk waves, and proper thickness ratios should be chosen.