光学计量在新旧动能转换中的发展

在新旧动能转换的新形势下,对光学计量专业发展来说是新的机遇,同时也面临着新的挑战。本文从光学计量的专业角度出发,结合光学计量的实际情况,提出了提升传统光学计量专业、发展新兴光学计量专业的新思路,并对光学计量在新旧动能转换的新形势下如何发展,以及发展过程中的机遇和挑战进行了思考和研究。     

Topograph for inspection of engine cylinder walls

The microstructural inspection of engine cylinder walls is an important task for quality management in the automotive industry. Until recently, mainly tactile methods were used for this purpose. We present an optical instrument based on microscopic fringe projection that permits fast, reliable, and nondestructive measurements of microstructure. The field of view is 0.8 mm x 1.2 mm, with a spatial sampling of 1100 x 700 pixels. In contrast to conventional tactile sensors, the optical method provides fast in situ three-dimensional surface characterizations that provide more information about the surface than do line profiles. Measurements are presented, and advantages of this instrument for characterization of a surface are discussed.     

Optical Microresonators for Sensing and Transduction: A Materials Perspective

Optical microresonators confine light to a particular microscale trajectory, are exquisitely sensitive to their microenvironment, and offer convenient readout of their optical properties. Taken together, this is an immensely attractive combination that makes optical microresonators highly effective as sensors and transducers. Meanwhile, advances in material science, fabrication techniques, and photonic sensing strategies endow optical microresonators with new functionalities, unique transduction mechanisms, and in some cases, unparalleled sensitivities. In this progress report, the operating principles of these sensors are reviewed, and different methods of signal transduction are evaluated. Examples are shown of how choice of materials must be suited to the analyte, and how innovations in fabrication and sensing are coupled together in a mutually reinforcing cycle. A tremendously broad range of capabilities of microresonator sensors is described, from electric and magnetic field sensing to mechanical sensing, from single‐molecule detection to imaging and spectroscopy, from operation at high vacuum to in live cells. Emerging sensing capabilities are highlighted and put into context in the field. Future directions are imagined, where the diverse capabilities laid out are combined and advances in scalability and integration are implemented, leading to the creation of a sensor unparalleled in sensitivity and information content.     

光电技术研究所的自适应光学技术

自适应光学是近二十年发展起来的光学新技术，它使光学系统具有能动地适应外界变化自动克服动态干扰的能力。十多年来光电技术研究所的自适应光学研究室建立了自适应光学技术的基础，研制成功多套自适应光学系统。带动了能动光学元件、微驱动技术和光束动态诊断技术等单元技术的发展。本文综合报导了这些技术进展。     

SOCRATE: an optical bench dedicated to the understanding and improvement of a laser conditioning process

We present an automatic excimer laser bench (SOCRATE) allowing for the treatment of optical components by laser conditioning. This apparatus, developed at the Commissariat a l'Energie Atomique-Le Ripault, has been designed to add to this conditioning process an in situ, accurate laser-induced damage threshold (LIDT) measurement and different nondestructive optical techniques for the characterization of the component during treatment. Through different examples, we demonstrate the importance of these characterizations to improve the understanding of the laser conditioning. The role of an in situ adapted metrology associated in real time with a laser conditioning bench offers new opportunities to analyze laser-induced damage mechanisms and subsequently to increase the LIDT of optical components.     

过焦扫描光学显微测量技术综述

随着半导体产业的发展和器件性能的不断提升,半导体器件的特征尺寸越来越小,器件结构越来越复杂,对检测仪器的性能提出了更高的要求。首先介绍过焦扫描光学显微法（Through-focus Scanning Optical Microscope,TSOM）的测量装置及测量原理,该方法可实现三维几何参数的无损测量,因其具有精度高、速度快、成本低等优点,可以满足在线测量的需求;然后从TSOM图构建和待测参数提取两个方面对TSOM方法的研究进展进行了梳理和归纳;最后对TSOM方法未来的研究重点和发展方向进行了展望。该方法有望为我国半导体制造产业提供新的检测手段,为优化和提升我国半导体制造工艺提供重要的技术支撑。     

光纤声传感器综述

光纤声传感器是一种利用光纤作为传光介质或探测单元的一类声传感器,相比传统电声传感器其具有灵敏度高、频带响应宽、抗电磁干扰等优越特性,可广泛应用于国防安全、工业无损检测、医疗诊断及消费电子等领域。按照声场与光的耦合方式,把光纤声传感器分为间接耦合型和直接耦合型两种,其中,间接耦合型光纤声传感器受声耦合材料频响特性限制,存在频响不平坦、带宽较窄及动态范围小等缺点;而直接耦合型光纤声传感器克服了上述的缺点,具有广阔的发展潜力。

     

嵌入式机器视觉光轴与物面垂直度调节新方法

为了提高二维视觉测量的精度,本文提出了一种嵌入式机器视觉光轴与物面垂直度调节的新方法(面积法).该方法将立体成像原理与数字图像处理结合,采用Harris算子与空间矩结合提取特征点亚像素坐标,利用海伦公式计算特定区域的面积,再根据相机镜头与被测物相对倾斜时特定区域的面积变化规律,准确的判断光轴与物面垂直度.实验证明,该方法操作简单,稳定性好,实用性强,能够很好的提高二维视觉测量的精度.该方法已应用在嵌入式机器视觉工业现场.     

Design Consideration to Reduce Cogging Torque in Axial Flux Permanent-Magnet Machines

In designing new topologies for permanent-magnet machines based on rare earth magnets, it is necessary to diminish the undesired cogging torque. This paper presents a 3-D finite-element analysis to evaluate the effect of magnet shape and stator displacement on cogging torque reduction, for axial flux machines. It analyzes the final electromagnetic torque for the proposed configurations. Finally, it presents the resultant cogging torque waveform for a 5.0 kW prototype, based on our optimization techniques.     

对计量内涵及其发展重点的思考

针对当前计量工作存在滞后于产业发展、与产业需求脱节的问题,从计量的基本理论、历史沿革和应用实践出发,通过分析计量的内涵、计量与测量的关系,并结合现阶段计量体系架构和实际工作开展情况,探讨计量工作在管理、技术和理念等方面存在的问题,聚焦测量需求、测量过程、测量标准、测量结果等测量体系组成要素,提出计量与产业融合发展的切入点,为当前质量强国、数字强国背景下充分发挥计量作用提供参考。     

Near-field optical sensors for particle shape measurements

Two new optical particle shape sensors are introduced. By placing them directly in the near-field of the particle projection (Fresnel region), no lenses or additional optical components are required to obtain particle images. Besides size information, accurate shape information is also obtained. Simulations show that distortion by diffraction is limited and can be reduced even further. Both static and dynamic measurements have been performed, which show that the sensors work as predicted by theory. The sensors have been developed to be applied in a microfluidic cytometer.     

Round Robin for Optical Fiber Bragg Grating Metrology

NIST has administered the first round robin of measurements for optical fiber Bragg gratings. We compared the measurement of center wavelength, bandwidth, isolation, minimum relative transmittance, and relative group delay among several grating types in two industry groups, telecommunications and sensors. We found that the state of fiber Bragg grating metrology needs improvement in most areas. Specifically, when tunable lasers are used a filter is needed to remove broadband emissions from the laser. The linear slope of relative group delay measurements is sensitive to drift and systematic bias in the rf-modulation technique. The center wavelength measurement had a range of about 27 pm in the sensors group and is not adequate to support long-term structural monitoring applications.     

Improvements of optical tactile sensors for robotic system by gold nanocomposite material

In this work we propose the evolution of a new class of optical pressure sensors suitable for robot tactile sensing. The sensors are based on a tapered optical fiber, where optical signals travel embedded into a PDMS-gold nanocomposite material. By applying different pressure forces on the PDMS-based nanocomposite we measure in real time the change of the optical transmitted intensity due to the coupling between the gold nanocomposite material and the tapered fiber region. The intensity reduction of the transmitted light intensity is correlated with the pressure force magnitude.     

纺织复合材料预制体成型过程无损检测技术研究进展

纺织复合材料多为各向异性材料,其力学性能很大程度上取决于成型后预制体内纤维的取向.为确保预制体成型后纤维的取向符合产品设计的要求,目前已有多种无损检测技术为纺织复合材料预制体成型过程及质量的检测提供服务.本文结合纺织复合材料预制体织造技术的发展趋势及预制体成型过程对无损检测的需求,就目前广泛用于科研和产业化生产当中的多...     

相移条纹投影三维形貌测量技术综述

结构光三维形貌测量系统目前得到了越来越广泛的应用和研究,相移条纹投影三维形貌精密测量技术是其重要的发展方向。对结构光相移条纹投影三维形貌测量系统的应用发展、工作过程、不同系统构成方式、相移条纹的各种形式及特点、相位误差校正方法、不同相位解包裹算法及其优缺点和适用场合、测量系统数学模型的实现方法及其相应的优缺点、高动态范围测量技术等进行了详细的分析。对相移条纹投影系统的工作流程、实现方法、关键技术的发展及其存在问题等进行了比较全面的梳理,为三维形貌精密测量技术进一步满足先进制造中更高精度的要求指出了后续的研究方向。     

微腔光频梳的应用研究进展

微腔光频梳作为一种频率的测量工具,具有高准确度、可集成化的优势,将在深空探测、精密计量等领域发挥巨大作用。本文系统全面地介绍了微腔光频梳在非线性激发产生和器件研制方面的技术现状,阐述了微腔光频梳在光钟、测距成像、光谱分析、频率合成器、低信噪微波源和相干通信等方面的研究进展,对光频梳未来的技术研究热点和应用前景进行了预测,为微腔光频梳在计量、测试、通信等领域的应用发展起到推动作用。     

光空间调制技术的研究进展

光空间调制(OSM)作为一种新型的光多输入多输出(OMIMO)技术,利用空间域激光器索引号额外携带信息,有效地提高了系统的传输速率和能量效率;同时,由于每符号周期仅激活一个激光器传递信息,较好地解决了传统OMIMO系统中的信道干扰和同步等问题。本文首先介绍了现有的几种光空间调制技术,概括和总结其在国内外的研究现状。此外,从传输速率、频谱效率、误码率(BER)和计算复杂度等四个方面对现有的OSM、光空移键控(OSSK)、增强型光空间调制(EOSM)和差分光空间调制(DOSM)等方案进行了比较分析。最后,指出了OSM中亟需解决的关键性问题及其未来的发展方向。     

Shannon's theory in nonlinear systems

An exponential growth in the capacity of optical networks has taken place over the last decade, but the extent to which future capacity growth can continue is limited by physical laws governing signal propagation through optical fibres. While the classic theory of communication developed by Claude Shannon allows the analytical calculation of information spectral density limits for linear channels with white additive Gaussian noise, the nonlinear nature of optical fibres makes these limits much more difficult to determine for long-haul optical transmission. Accurately predicting the ultimate limits has been the focus of much recent research. This paper describes the sources of linear and nonlinear signal impairments, reviews progress on extending Shannon's theory to the case of nonlinear signal propagation, and discusses new optical and electronic signal processing techniques that may be used to approach the Shannon limit in future networks.     

Efficient encoding algorithms for computer-aided design of diffractive optical elements by the use of electron-beam fabrication

One of the general requirements of a computer-aided design system is the existence of efficient (in data size and running time) algorithms that are generally reliable for the broadest range of design instances. The restricted data formats of the electron-beam machines impose difficulties in developing algorithms for the design of diffractive optical elements (DOE's) and computer-generated holograms (CGH's). Issues that are related to the development of CGH algorithms for e-beam fabrication of DOE's and CGH's are discussed. We define the problems the CGH algorithms need to solve, then introduce general curve drawing algorithms for the e-beam data generation of diffractive optical components. An efficient algorithm for general aspherical DOE's is proposed. Actual design and fabrication examples are also presented.     

Tactile sensor based on piezoelectric resonance

We discuss here the realization of tactile sensors based on the principle of change in piezoelectric resonance frequency with the applied pressure. An array of electrodes has been adopted on either side of the PZT material to have independent resonators. The common areas sandwiched between the electrodes and excitable at resonance frequency of the PZT material are used to form the sensitive area of the tactile sensor. The electrodes were deposited using sputtering technique. Tactile sensors with 3/spl times/3, 7/spl times/7, and 15/spl times/15 array of electrodes are developed with different electrode dimensions and separation between the electrodes. The tactile sensor has been interfaced to computer for the convenience of automatic scanning and making it more user interactive. The tactile sensors developed with different spatial resolution were tested for different shaped objects placed in contact with the sensor. The 3/spl times/3 matrix tactile sensor showed relatively poor spatial resolution, whereas the 15/spl times/15- matrix tactile sensor showed improved spatial resolution. The sensor with 7/spl times/7 matrix elements was tested for its sensitivity to different extents of applied force/pressure. The output response study carried out on the sensors indicated that these sensors can provide information not only about the extent of force/pressure applied on the object, but also the contour of the object which is in contact with the sensor.