硅微ZnO压电薄膜传声器的研制

本文介绍了一种利用ZnO压电薄膜为换能器的硅微压电薄膜传声器的制备,并且对微机械加工工艺过程进行了较为详细的描述。本文对传声器的部分结构进行改进,与通常设计相比较大幅提高了传声器的性能,1000Hz基准频率的灵敏度达到-85dB(相对于1V/Pa),500Hz到10000Hz的频率响应的平坦度在±3dB范围内。     

利用Doppler效应设计的可变指向性传声器

在天线工程的领域中,尖锐的指向性是很容易用波干涉的原理获得的。在声学领域中,利用同一原理,曾作过很多努力来实现尖锐指向性的传声器。但是,由于这类传声器必须在声讯号波长相当宽的范围内工作,所以已研制出的任何这类传声器,指向性都不是很满意的。因此,必须引进新的原理来设计指向传声器。     

光栅衍射的微课视频设计与制作

信息技术的发展不断促进教育模式的变革,基于互联网的微课教学可谓是近年的热门教学模式。大学物理实验是物理学专业学生的一门重要课程,但其传统授课方式存在不足。将微课与大学物理实验教学结合起来,不但能提升教学效果,还能提高学生的学习主动性。光栅衍射在光学课程中处于重要地位,学生在理论学习中只理解了光栅衍射的原理,对于其应用不太熟悉。本文从教学设计、课件制作、脚本设计、视频制作方面介绍了光栅衍射的微课视频设计与制作过程,对探索大学物理实验教学新模式有一定意义。     

利用双光栅衍射测量微谐振动的研究

本文以余弦光栅为模型,运用波前相因子分析方法,得到了有一定距离的双余弦光栅衍射斑的强度公式.推导出了双光栅之一作纵向或横向微谐振动时,远场衍射光斑强度的变化公式.这些公式呈现出复合余弦函数的变化规律,并且分析出了光强随时间的变化与光栅振幅之间的关系.为微小振动的测量提供了一种新的方法.最后,文章给出了衍射斑强度变化信号...     

硅传声器微型化的研究进展

引言电声设备或系统中,电声器件（如传声器、扬声器山、送话器、受话器等）的作用显得特别重要,它们的性能与质量往往会决定电声设备或系统的水平,所以电声器件的研究开发和进展会引起声学界各方面的关注、1999年3月在柏林召开的第25届德国声学DAGA会议上,若干集体报道了把改变传声器标准元件为硅片构件的进展。1历史背景小型驻极体传声器在国外70年代末和80年代初美国、瑞士、荷兰等国就解决了研究这种电声器件的关键设计和制造工艺技术,推出了系列产品并己广泛应用。国内于80年代中期研制小型驻极体传声器,1988年在我国已研制出第…     

衍射光栅的实验设计

本文介绍了一种用可调角度双面镜产生相干光的干涉方法制做衍射光栅，所用仪器不多，光路简明     

衍射光栅的改进

在原有光栅上方镀上双面反射镜，这种改进后的光栅可替代附件平面镜，减少了实验步骤，方便了光栅平面的调节，降低了测量误差．     

反射式单级衍射光栅

介绍了单级衍射光栅的发展趋势, 从理论上论证了单级衍射光栅的可行性, 引入了一种新型衍射光学元件—-准正弦反射式单级衍射光栅(QSRG). 它能有效抑制高级衍射, 可用于提高光谱系统的信噪比和精度. 而通过QSRG的实验结果也验证了此新型色散元件确实具有良好的单级衍射特性, 二级及以上的高级衍射被有效地抑制, 与理论预测几乎一致. 本文的结果可望在反射式光谱测量系统中得到广泛应用.     

多级衍射全息光栅

提出用Mach-Zehnder 干涉仪两步记录制作具有多级衍射的全息光栅方法。详细描述这种方法的原理,并提供了光栅样品的傅里叶谱及用这种多级衍射光栅实现图像多重的实验结果。     

衍射光栅刻划机

本文介绍了长春光学精密机械研究所研制成功的四台衍射光栅刻划机。该机自1958年开始设计。1号、2号光栅刻划机为机械型,分别于1959年、1965年安装调试完毕。3号、4号光栅刻划机为光电干涉控制型,分别于1970年、1975年制成,每台光栅刻划机都有自己的特点。4号机连续运动时的锁相误差平均为1/100条纹,个别的最大不超过1/36条纹。利用这些类型的光栅刻划机已刻划出许多平面光栅,最大的刻划宽度达185毫米,刻线密度从每毫米60条到1200条。实测分辨本领最高达20万,相对效率最高达90％,一级罗兰鬼线最低为4×10~(-5),赖曼鬼线观察不到。     

Mach-Zehnder interferometric optical switch with MEMS phase shifter

We propose a novel Mach-Zehnder interferometric optical switching device with micro-electro-mechanical systems (MEMS) phase shifters. Analytical results show that the stretch length per phase shifter is 70 nm at an applied voltage of 100 V. Phase switching can be achieved by the cascade connections of fifteen phase shifters.     

强度解调的F-P干涉型光纤传声器

F-P干涉型光纤传声器具有灵敏度高、结构简单、抗电磁干扰等优势,论文针对基于强度解调的F-P干涉型光纤传声器展开研究。采用多光束干涉理论建立了系统光学模型,采用薄板小挠度弯曲理论建立了传声器振膜的声学模型,在此基础上得到传声器灵敏度的表达式。通过理论分析和仿真,得到了敏感单元结构参数对传声器灵敏度和响应频率的影响关系,并对F-P敏感结构的腔长和端面反射率进行了优化设计。应用厚度为3μm的镍膜,研制出光纤传声器样机,测得其灵敏度为268 mV/Pa、频响特性为±3 dB@50 Hz~4 kHz,可应用于恶劣环境下的声音传感。     

A comparison measurement of nonlinear ultrasonic waves in tubes by a microphone and by an optical interferometric probe

This paper deals with the analysis of ultrasonic fields inside waveguides generated by ultrasonic waves of high amplitude. These waves behave nonlinearly, so it is not possible to use standard linear equations to describe their behaviour. Therefore, we started with an experimental determination of the acoustic pressure of air in glass tubes. We chose two methods of measurement--by a microphone and by an optical interferometric probe. The conventional method by a microphone creates numerous problems, which can be avoided by using an optical method, a heterodyne laser interferometer.     

New silicon-based fibre assemblies for applications in integrated optics and optical MEMS

Nearly closed rhombus-shaped channels in micromachined silicon with very high accuracy for fibre array assemblies are presented. The fabrication and the assembly of fibres are described. The achieved accuracy is comparable with conventional V-groove assemblies. Additionally, rhombus-shaped channels allow new applications such as monitor pigtails with integrated photodiodes or buried fibre supplies in optical MEMS. Received: 22 May 2001 / Revised version: 7 September 2001 / Published online: 30 October 2001     

一种光电数字传声器的设计

本文介绍了一种新颖光电传声器的设计，它不采用Ａ／Ｄ转换器而直接输出数字信号，文中介绍了与传声器有关的光学扫描系统，光栅探测器的工作原理和设计参数。     

White light interferometric detection of unpolarized light for complete Stokesmetric optical coherence tomography

Optical coherence tomography (OCT) relies on interference between a polarized reference and the target reflection. Thus, it has generally been impossible to detect any unpolarized part in the signal. Here, we demonstrate a scheme that overcomes this limitation. Using a combination of heterodyning and filtering, we realize a polarization-sensitive OCT system capable of measuring the full Stokes vector, including the depolarized part. Based on such a system, we perform full Stokesmetric imaging of different layers in a porcine tendon sample. The complete 4 × 4 backscattering Muellermetric images of one layer are acquired and investigated.     

Contrast ratio and hysteresis width of optical bistability in quantum-dot vertical-cavity semiconductor optical amplifiers integrated with MEMS membrane

The characteristics of optical bistability in quantum dot vertical cavity semiconductor optical amplifier integrated with MEMS membrane have been investigated, and a closed-form model is derived taking into account the effect of the quantum dot discrete states and the membrane deflection and reflectivity. We show that small membrane deflection significantly adjusts the resonant wavelength, the contrast ratios and the hysteresis width. The shape of the input–output characteristics of the device can be adjusted to display clockwise, butterfly and counterclockwise hysteresis loops depending on the membrane deflection and the initial wavelength detuning. Our analysis reveals that the contrast ratios of the upper and lower bistable levels are totally different. Also, it has been shown that the characteristics of the bistability are strong function of the active layer linewidth enhancement factor and the membrane reflectivity.     

Higher-order optical resonance node detection of integrated disk microresonator

We have demonstrated higher-order optical resonance node detection by using an integrated disk microresonator from through port of the coupling bus waveguide. In addition to the fundamental mode, the disk resonator has higher-order whispering gallery modes. The excited second-order higher-order mode has a node at the position where the electromagnetic energy of the fundamental mode is close to a maximum. This high resolution measurement of optical resonance mode profile has a variety of applications for optical sensing and detection. The self-referencing characteristics of the two optical resonance modes have potential to achieve optical detection independent of external perturbation, such as temperature change.     

Nonlinear model and system identification of a capacitive dual-backplate MEMS microphone

This paper presents the nonlinear identification of a capacitive dual-backplate microelectromechanical systems (MEMS) microphone. First, a nonlinear lumped element model of the coupled electromechanical microphone dynamics is developed. Nonlinear finite element analyses are performed to verify the accuracy of the lumped linear and cubic stiffnesses of the diaphragm. In order to experimentally extract the system parameters, an approximate solution using the second-order multiple scales method is synthesized for a nonlinear microphone model, subject to an electrical step input. A nonlinear least-squares technique is then implemented to extract system parameters from laser vibrometry data of the diaphragm motion. The results indicate that the theoretical fundamental resonant frequency, damping ratio and nonlinear stiffness parameter agree with the corresponding extracted experimental parameters with 95% confidence interval estimates.