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针对超精密运动台的二维亚微米级精度同步测量需求,提出并建立了平面反射式二维光栅测量系统,研究了平面反射式二维光栅的平面位移同步测量方法,分析了平面反射式二维光栅测量系统的误差传递模型。通过Vold-Kalman滤波算法,对光栅信号中存在的高次谐波误差、幅值/相位误差进行实时修正和滤除。采用反正切细分算法和周期测量法对光栅正交脉冲的频率进行测量,实现对被测目标的高分辨率测量和实时运动速度测量。同时,构建了亚微米级测量精度的平面反射式二维光栅测量系统,测量范围为500 mm×500 mm,x、y方向的定位精度为±0.3μm,测量分辨率为0.005μm。 相似文献
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光纤光栅二维加速度传感器 总被引:3,自引:0,他引:3
提出了一种基于"钢管-质量块"弹性结构体的光纤光栅(FBG)加速度传感器,4个光纤光栅粘贴在质量块一侧的钢管表面应变的最大处,光栅分布在沿钢管圆周呈90°方位角的位置上,粘贴方向沿钢管的轴向。通过两两组合的光栅对的波长变化量的差值感测弹性结构体不同方向的振动加速度,实现二维测量及温度补偿。使用有限元软件进一步分析说明了传感器的测量原理及谐振频率。传感器性能参数测试结果表明,该传感器谐振频率为515Hz,与有限元分析结果基本吻合,灵敏度为0.88pm·m-1·s2,加速度测量范围为15~75m/s2;传感器二维振动测试结果良好,具备较好的抗干扰振动能力。 相似文献
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文章提出了一种以衍射光栅为基准件的二维纳米位移测量系统,阐述了系统的组成和光路结构.分析了系统的测量原理。最后利用Lighttools软件对系统的光学结构进行仿真设计,研究系统干涉信号的变化规律,为后续的光路优化和误差补偿提供了理论模型。 相似文献
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现有光栅衍射型激光告警中,正弦光栅存在1级衍射效率较低,闪耀光栅在闪耀波长附近0级和-1级衍射效率很低,这两种光栅的缺点都降低了激光告警的可靠性。为此文中提出了一种改进型闪耀光栅。将两闪耀光栅反相对接,并且中间留一定无光栅空间,此改进可提高波长在闪耀波长附近0级和-1级的衍射效率,将有效克服传统闪耀光栅的漏报警现象。设计加工了闪耀波长为800 nm的改进型闪耀光栅,理论分析了0级和1级衍射效率;采用波长为808 nm和850 nm的光,对改进型闪耀光栅进行二维激光告警实验测试,实验结果表明,在波长为闪耀波长附近光入射时,改进型较普通闪耀光栅的0级和-1级衍射强度有很大提高,能够被CCD有效探测。该改进型闪耀光栅可有效提高二维激光告警系统的可靠性。 相似文献
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为了实现两个方向的振动信号检测,提出了一种以杆为弹性结构的二维光纤光栅振动传感器。首先对该传感器进行了理论分析,并推导出其固有频率和灵敏度公式。然后对传感器结构进行了优化仿真,确定各个参数的最终值。最后通过实验研究了传感器的各项性能。实验结果表明,该传感器在x方向上的固有频率为493 Hz,灵敏度为54 pm/g,线性度为99.9%;在y方向上的固有频率为466 Hz,灵敏度为5 pm/g,线性度为97.5%。此外,采用双光纤光栅消除了温度对振动信号测量的影响,温度灵敏度为0.1 pm/°C。该传感器结构简单,可检测两个方向的振动信号,消除了温度的影响,在振动信号检测中表现良好,因此在多维振动信号检测领域具有重要研究意义。 相似文献
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Blazed diffraction gratings fabricated using X-ray lithography: fabrication, modeling and simulation
Diffraction gratings are used in optical communications devices, spectrographs, optical scanners, monochromators, and in other instances. Diffraction gratings are either transmission or reflection. Reflective gratings are, usually, either ruled or holographic. Blazed gratings (step-echelette or phase gratings) are non-planar gratings. We present the fabrication of blazed diffraction gratings using X-ray lithography. We model, theoretically, the development process of X-ray exposed X-ray sensitive resist material (polymethyl methacrylate), and we establish a simulation algorithm, the ray-tracing algorithm based on the Hamilton–Jacobi equation. Theoretical predictions based on simulation results validate fully the fabricational results. 相似文献
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The inverse problem of electrocardiology aims to reconstruct the electrical activity occurring within the heart using information obtained noninvasively on the body surface. Potentials obtained on the torso surface can be used as input for the inverse problem and an electrical image of the heart obtained. There are a number of different inverse algorithms currently used to produce electrical images of the heart. The relative performances of these inverse algorithms at this stage is largely unknown. Although there have been many simulation studies investigating the accuracy of each of these algorithms, to date, there has been no comprehensive study which compares a wide variety of inverse methods. By performing a detailed simulation study, we compare the performances of epicardial potential [Tikhonov, Truncated singular value decomposition (TSVD), and Greensite] and myocardial activation-based (critical point) inverse simulations along with different methods of choosing the appropriate level of regularization (optimal, L-curve, composite residual and smoothing operator, zero-crossing) to apply to each of these inverse methods. We also examine the effects of a variety of signal error, material property error, geometric error and a combination of these errors on each of the electrocardiographic inverse algorithms. Results from the simulation study show that the activation-based method is able to produce solutions which are more accurate and stable than potential-based methods especially in the presence of correlated errors such as geometric uncertainty. In general, the Greensite-Tikhonov method produced the most realistic potential-based solutions while the zero-crossing and L-curve were the preferred method for determining the regularization parameter. The presence of signal or material property error has little effect on the inverse solutions when compared with the large errors which resulted from the presence of any geometric error. In the presence of combined Gaussian and correlated errors representing conditions which may be encountered in an experimental or clinical environment, there was less variability between potential-based solutions produced by each of the inverse algorithms. 相似文献
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A microstructured fibre Bragg grating that relies on a partial and localised etching of the cladding layer along the grating region is proposed. The main effect is the formation of defect states inside the bandgap depending on surrounding refractive index. This leads to the possibility of realising novel optoelectronic devices for sensing and telecommunication applications. 相似文献
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聚合物光纤光栅不仅具有体积小、质量轻、柔软、成本低等诸多优点,还因聚合物自身的特性而具有灵敏度高、响应范围宽、生物兼容性等优良特性。首先梳理了聚合物光纤的光敏性机理,概述了聚合物光纤光栅制备的刻蚀光源和方法;其次根据聚合物光纤的组成材料,概述了多种聚合物光纤光栅的制备进展和性能指标,包括聚甲基丙烯酸甲酯、环烯烃共聚物TOPAS、透明无定物氟聚合物CYTOP和聚碳酸酯。总之,目前聚甲基丙烯酸甲酯聚合物光纤光栅的研究占主导,而基于新型材料的聚合物光纤光栅因自身独特的优势也逐渐受到重视。 相似文献
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研究基于二元光学的达曼光栅理论和设计方法,设计5×5分束达曼光栅。分别采用“减法”和“加法”加工方案制备器件。“减法”工艺方案包括,优化了氧化硅光栅制作中曝光、显影及深刻蚀工艺参数等关键工艺技术;“加法”工艺方案研究了氮化硅薄膜的制备及刻蚀工艺的问题。研究并制备了两种工艺方法的达曼光栅器件。实验结果表明,“减法”工艺方案的零级衍射场均匀分布的5×5点阵,总的衍射效率达到53%,不均匀性仅为0.19%;“加法”工艺方案的总的衍射效率为59%,不均匀性仅为0.16%;实验结果与理论设计的相符,验证了理论设计与工艺技术的可靠性。 相似文献
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两维LED显示屏制作浅析 总被引:3,自引:0,他引:3
阐述了大屏面两维发光二极管(LED)显示屏的设计、制造及其在虚拟显示样机像源中的应用。对LED阵列亮度的均匀性作了分析。典型的取样图像、图形及灰度图像皆证明LED阵列的性能可用作虚拟显示的单色檬源。 相似文献
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近年来,随着微机电系统、显微医疗和组织工程等领域技术水平的快速发展,微操作技术引起了科研界和产业界的广泛关注,其对于未来的微纳技术的小型化、功能化和集成设备的制造有着至关重要的作用。利用飞秒激光双光子聚合技术加工的微结构,其尺寸处于微观尺度,质地较脆、黏着力大、尺度效应显著,且微结构所受到的表面力逐渐取代重力起主导作用,以上因素进一步增加了微操作的难度。因此,一种基于毛细作用的玻璃毛细管吞吐微结构的微操作装置被提出,利用毛细力将微结构拾取和移动,再将不同的微结构装配在一起。该方法不仅能将微型原件进行组装,而且能将不同材料、不同特性的微型器件组装在一起,形成复杂的混合微结构。 相似文献