二维方型位置敏感探测器线性度的研究

研讨位置敏感探测器(PSD)的线性度问题,对影响二维方型结构PSD的线性度的三种因素,即边框区电阻率,负载电阻以及分流电阻的均匀分布进行模拟仿真实验研究,得到了相应的电流—位置图,并对其进行了分析,得出边框电阻和负载电阻越小,分流面电阻越均匀,从而线性度越好,位置误差也越小的结论,为进一步提高二维方型结构PSD的线性度提供了途径。     

Absolute beam brightness detector

In generally accepted emittance measurement, main attention is concentrated on emittance areas ?(x), ?(y) occupied by desired part of ion beam in transverse phase space and shape of these areas. The absolute beam phase density (brightness) as usually is not measured directly and the average beam brightness B is calculated from a beam intensity I and the transverse emittances. In the ion source and low energy beam transport (LEBT) optimization, it is important to preserve the beam brightness because some aberration of ion optic and beam instabilities can decrease the brightness of the central part of ion beam significantly. For these brightness measurements, it is convenient to use an absolute beam brightness detector with the brightness determination from one short considered in this article.     

位置敏感探测器（PSD）的研究进展

回顾了位置敏感传感器(PSD)的发展历史,介绍了各种光敏面结构的PSD。并结合研究成果,阐述了单晶硅、氢化非晶硅、有机材料、大面积挠性薄膜、CMOS型,一维及二维阵列PSD等采用各种组成材料和工艺制作的PSD的发展现状,并对今后的发展和研究方向进行了展望。     

High speed tooling

Creating tooling for a new product can be a long and expensive process. The authors explore the use of rapid prototyping technology for producing metal tools     

High speed nano-metrology

For manufacturing at the nanometre scale a method for rapid and accurate measurement of the resultant functional devices is required. Although atomic force microscopy (AFM) has the requisite spatial resolution, it is severely limited in scan speed, the resolution and repeatability of vertical and lateral measurements being degraded when speed is increased. Here we present a new approach to AFM that makes a direct and feedback-independent measurement of surface height using a laser interferometer focused onto the back of the AFM tip. Combining this direct height measurement with a passive, feedback-free method for maintaining tip-sample contact removes the constraint on scan speed that comes from the bandwidth of the z-feedback loop. Conventional laser reflection detection is used for feedback control, which now plays the role of minimising tip-sample forces, rather than producing the sample topography. Using the system in conjunction with a rapid scanner, true height images are obtained with areas up to (36 × 36) μm(2) at 1 image/second, suitable for in-line applications.     

Avalanche photodiode based detector for beam emission spectroscopy

An avalanche photodiode based (APD) detector for the visible wavelength range was developed for low light level, high frequency beam emission spectroscopy (BES) experiments in fusion plasmas. This solid state detector has higher quantum efficiency than photomultiplier tubes, and unlike normal photodiodes, it has internal gain. This paper describes the developed detector as well as the noise model of the electronic circuit. By understanding the noise sources and the amplification process, the optimal amplifier and APD reverse voltage setting can be determined, where the signal-to-noise ratio is the highest for a given photon flux. The calculations are compared to the absolute calibration results of the implemented circuit. It was found that for a certain photon flux range, relevant for BES measurements (≈10(8)-10(10)?photons/s), the new detector is superior to both photomultipliers and photodiodes, although it does not require cryogenic cooling of any component. The position of this photon flux window sensitively depends on the parameters of the actual experimental implementation (desired bandwidth, detector size, etc.) Several detector units based on these developments have been built and installed in various tokamaks. Some illustrative results are presented from the 8-channel trial BES system installed at Mega-Ampere Spherical Tokamak (MAST) and the 16-channel BES system installed at the Torus Experiment for Technology Oriented Research (TEXTOR).     

Note: High speed optical profiler based on a phase-shifting technique using frequency-scanning lasers

We present a high speed optical profiler (HSOP) using frequency-scanning lasers for three-dimensional profile measurements of microscopic structures. To improve upon previous techniques for implementing the HSOP, we developed frequency-scanning lasers and a compact microscopic interferometer. The controller of the HSOP was also modified to generate proper phase-shifting steps. For measurements of step height specimens, the HSOP showed results comparable with a commercial optical profiler, even with much higher measurement speeds (up to 30 Hz). The typical repeatability of step height measurement was less than 1 nm. We also present measurements of microscopic structures to verify the HSOP's ability to perform high speed inline inspection for the semiconductor and flat-panel display industries.     

光电位置传感器PSD特性及其应用

对光电位置传感器 PSD的结构、工作原理、特性进行了分析和概述 ;并介绍了PSD在二维定位测量中的应用 ;最后分析了造成系统误差的主要原因     

数控机床位置检测元件检修注意事项

阐述娄控机床位置检测元件的维修注意事项及进口件用国产件的替代。     

光电位置传感器PSD特性及其应用

对光电位置传感器PSD的结构、工作原理、特性进行了分析和概述;并介绍了PSD在二维定位测量中的应用;最后分析了造成系统误差的主要原因.     

光电位置传感器PSD特性及其应用

对光电位置传感器PSD的结构、工作原理、特性进行了分析和概述;并介绍了PSD在二维定位测量中的应用;最后分析了造成系统误差的主要原因.     

二维频域光学相干层析系统研究

针对时域光学相干层析成像系统的成像速度较慢的问题,采用VC++与Matlab混合编程技术开发了二维频域光学相干层析成像系统,实现了对被测样品进行内部快速成像;搭建二维频域光学相干层析成像系统代替一维频域光学相干层析成像系统;利用计算机驱动面阵CCD相机对干涉信号进行采集得到干涉信号;采用计算机驱动NI卡对压电陶瓷(PZT)移相器进行相移控制以达到频域光学相干层析成像系统对移相的需求,利用计算机驱动线性电动移动平台实现检测样品进行横向扫描以达到对样品进行三维成像。研究结果表明,该系统集成度高,开发的软件功能齐全、界面友好、便于维护和升级;该二维系统相比一维光学相干层析成像系统而言减少了一维的扫描采集次数,大大提高了成像速度。     

High speed electrochemical boring

Electrochemical machining (ECM) is widely used nowadays in a great variety of processes, especially in the aero and auto industries. The main machining processes, where high tool feed rates are required, are drilling, cavity sinking, broaching and grinding. In addition, the non-equilibrium machining processes, where stationary electrodes are utilized, have important practical applications in the fields of deburring and embossing. Electrochemical honing is a non-equilibrium process. EC honing is a new technique which, in spite of being used in some industrial plants, is still not fully described, requiring more information about the process. This work presents a comparative study, between rotating and non-rotating electrodes for the enlargement of conventionally pre-drilled holes. The comparison covers the rate of metal removal, dimensional accuracy, surface finish and power consumption. The beneficial advantages of using high rotational speeds on component accuracy are verified. The results emphasize that each process has its own particular characterization, appropriate field of application and tooling system.     

基于CCD的双光束多波长紫外可见吸收检测器

由于传统的多波长紫外可见吸收检测器无法克服光源波动造成的噪声和漂移,故设计开发了一种基于CCD的双光束多波长紫外可见吸收检测器.光源发出的光聚焦后被分束镜分成信号光和参考光,信号光射入到样品检测池中.从样品检测池中出射的信号光经过斩光器聚焦在狭缝上,被凹面光栅分光成像于CCD的一部分光敏面上.参考光在CCD的另一部分光敏面上分光成像.在光路系统和外围电路的辅助配合下,可以用一片CCD实现信号光谱,参考光谱和暗电流的精确测量.由于采用参考光光谱和CCD暗电流对信号光谱进行实时补偿,可以使基线短期噪声降低为1×10-5 AU,漂移降低为1×10-4 AU/h.     

Spectral-domain phase microscopy with improved sensitivity using two-dimensional detector arrays

In this work we demonstrate the use of two-dimensional detectors to improve the signal-to-noise ratio (SNR) and sensitivity in spectral-domain phase microscopy for subnanometer accuracy measurements. We show that an increase in SNR can be obtained, from 82 dB to 105 dB, using 150 pixel lines of a low-cost CCD camera as compared to a single line, to compute an averaged axial scan. In optimal mechanical conditions, phase stability as small as 92 μrad, corresponding to 6 pm displacement accuracy, could be obtained. We also experimentally demonstrate the benefit of spatial-averaging in terms of the reduction of signal fading due to an axially moving sample. The applications of the improved system are illustrated by imaging live cells in culture.     

基于光纤传感的乳化液浓度检测仪的设计

乳化液作为液压支架的传动介质,其浓度大小直接影响液压支架和支柱的工作寿命及成本,因此对乳化液浓度严格检测十分必要。基于光纤的宏弯损耗原理,提出一种光纤乳化液浓度检测仪的设计方案,分析了影响损耗的因素,另外对乳化液的折射率特性进行了测试实验,分析了乳化液浓度与其折射率之间的关系,介绍了检测仪的系统组成和软、硬件设计。这种光强调制型光纤传感器结构简单,具有灵敏度高、抗电磁干扰和耐腐蚀的特点,能够实现对乳化液浓度的在线检测。     

Optoelectronic detector probes for scanning near-field optical microscopy

A brief explanation of the optoelectronic probe concept and a comparison between the implementation of passive waveguide probes and optoelectronic probes in scanning near-field optical microscopy (SNOM) is presented. The first probe realizations using cleaved semiconductor crystals and the work at present in progress using microfabricated Si pyramids are described. These crystals with evaporated metal electrodes forming a slit aperture with subwave-length dimensions work as metal–semiconductor–metal photodetectors. Their optical detection behaviour is investigated by measuring the intensity distribution of a laser focal point. Measurements where the external bias voltage is changed show that it is possible to modify the detection behaviour of the device because of the varying depletion widths. The last part of the article describes a concept where pyramidal probes should function simultaneously as sensors for scanning force microscopy (SFM) to measure topography and as optoelectronic probes for scanning near-field optoelectronic microscopy (SNOEM).     

V型耦合式刀片低能束流位置探测器及其性能检测

基于合肥国家同步辐射实验室(NSRL)低能量真空紫外光源的特点,研制了耦合式刀片低能束流位置探测器,用于在线监测波荡器辐射出的低能量真空紫外相干光源的稳定性.探测器采用V型耦合式刀片作为探针,基于错位安装、倾斜嵌入被测光束边缘和直流偏压捕集自由电子等技术有效增强光电效应,提高探针的响应灵敏度和探测器监测精度.介绍了耦合式刀片低能束流位置探测器的结构特点、探测原理和性能测试,在线监测了NSRL波荡器光源的稳定性,获得了一系列有价值的试验数据.结果表明:该探测器能完成NSRL-0.8GeV低能储存环上插入件光源的在线监测,满足对改造后的新光源各插入件辐射光束位置稳定监测的要求.