相位扫描法制作变栅距光栅

提出了一种制作变栅距(VLS)光栅的相位扫描方法。该方法的主要装置包括一个用于控制刻划机运动的光栅干涉仪和一个相位扫描机构。如果调整光栅干涉仪,保证接收场中只有两条干涉条纹,然后改变用于对条纹进行计数的光电传感器的位置,就可以刻划出具有变栅距的刻槽。对光电式光栅刻划机的控制系统和结构都做了详细论述。按照上述方法成功刻划出了试验性的VLS光栅,它的最小栅距增量为0.33nm,并对在制作过程中产生的误差进行了讨论。采用测量衍射角的方法进行了栅距检测试验,由变栅距光栅和等栅距光栅作出的拟合曲线表明:相位扫描方法是加工具有亚纳米栅距增量的VLS光栅的有效方法,该方法对超精密定位也具有借鉴作用。     

光栅位移测量系统的误差自修正方法研究

文中介绍的误差自修正方法是通过光栅位移测量系统中单片机对光栅传感器的多个零位信号进行计数,并根据测量值和系统设定值得到的误差函数自动进行误差修正.实验结果表明,该方法对光栅位移测量系统的误差既可自动进行有效的修正,又可提高系统的测量精度.     

一种非线性误差修正方法

对于采用光栅做位移传感器的长度测量仪器,为提高仪器测量准确度,多采用误差修正的方法,来减小仪器示值误差。本文介绍了一种非线性误差修正方法,该方法在国外有的仪器上已被采用,作者也做过试验,验证了方法的可行性。     

纳米光栅栅距的精确测量与nano4国际比对

对Littrow衍射方法测量纳米光栅的基本原理、构造及其安装误差进行了分析研究,并利用所建立的测量装置参加了国际计量技术委员会长度咨询委员会组织的一维纳米光栅国际比对.比对结果证明了该测量系统具有优良的计量性能,能够用于纳米光栅栅距的检定校准.     

自聚焦变栅距光栅设计、制作及特性研究

利用变栅距光栅的衍射光束自聚焦特性,设计和制作了变栅距透射光栅,并对其自聚焦特性进行了研究.采用变栅距光栅的自动生成宏文件程序,优化设计了变栅距光栅的栅距变化.采用光栅扫描电子束光刻的方法制作了中心线数为300 1/mm、适用于355 mm波长的自聚焦变栅距变狭缝光栅.使用三倍频Nd:YAG激光器,研究了制作的变栅距光栅的聚焦特性,并与对氦氖激光的聚焦特性进行了比较.结果表明,主动式设计的变栅距变狭缝自聚焦光栅可以大幅提高衍射光强度和分辨本领,具有重要的应用价值.     

光栅纳米测量中的系统误差修正技术研究

详细研究了光栅纳米测量系统的误差特性 ,以及利用激光干涉仪对高精度光栅测量系统的系统误差进行检测、并在信号处理中予以补偿和修正的方法。实验表明 ,通过这种系统误差修正方法对周期累计误差和细分误差同时进行修正 ,能够大幅度地将计量光栅系统的测量准确度从微米或亚微米量级提高到纳米级水平 ,以实现光栅纳米测量。     

长度光栅测量系统的误差修正技术

文章针对长度光栅测量系统的误差来源、特点提出了二次比对、拟合的修正方法。在文章所论述的方法中,通过光电显微镜、线纹尺、数据拟合工具将光栅位移长度溯源到激光波长;将生成的修正公式赋进长度光栅测量系统的程序中完成误差自动修正。文章提出的光栅测长系统的误差修正方法原理简单、实用、修正精度高。对于三坐标测量机、测长机、万工显等精密直线位移平台都具有借鉴和参考价值。     

高精度衍射光栅干涉仪的研制

提出了一种新型的激光衍射光栅干涉仪测量系统,以光栅衍射原理和偏振光学为理论基础,配合正交信号的解相位细分原理,使得该系统可以达到纳米级分辨率.由于光栅干涉测量系统以光栅栅距作为测量基准,相对于传统干涉仪,光栅尺系统受环境因素造成的测量误差影响较小.通过实验校正,得到不同行程范围内光栅干涉测量系统的纳米级重复性误差,新型的激光衍射光栅干涉仪测量系统适合于较长行程的高精度位移测量.     

一种高密度光栅结构光编码方法

针对光栅结构光传感器三维测量过程中光条识别问题,提出一种新的金字塔子光栅投射法结构光编码方法。该方法把高密度光栅逐级细分为若干个可容易识别的子光栅,用空间二分编码方法分别对每个子光栅进行编码,并详细介绍了确定光条点码值的方法。把该编码方法应用于光栅结构光传感器中,实现了维纳斯雕像的三维测量,并给出了三维重建结果。结果表明,该编码方法误码率仅为0.75%,特别适用于物体三维轮廓致密测量。     

长光栅测量系统误差修正方法

针对长光栅测量系统的误差特点提出了一种实用的综合修正方法.通过光电显微镜、线纹尺、数据拟合工具将光栅位移长度溯源到激光波长.提出的误差修正方法简单、实用、修正精度高.对于三坐标测量机、测长机等精密线位移平台都具有借鉴和参考价值.     

Optical grating diffraction method: from strain microscope to strain gauge

The grating diffraction method for direct strain measurement is reviewed. Two systems which use this method are presented. The first system is a compact strain microscope. A Leitz optical transmitting microscope with white light source is reconstructed by developing a loading and recording system. Gratings with median density of between 40 and 200 lines/mm are used. With the help of a Bertrand lens, the Fourier spectrum of the grating is formed with high image quality on the CCD sensor plane. Software is developed to precisely, quickly and automatically determine the diffraction spot centroids. The second system is a new strain sensor based on a high-frequency grating and two Position Sensor Detectors (PSDs). The grating, attached to the surface of the specimen, is illuminated by a focused laser beam, generally with a frequency of 1,200 lines/mm. The centroids of diffracted beam spots from the grating are automatically determined using two PSD sensors connected to a personal computer. The shift of diffracted beam spots due to specimen deformation is detected. Strain sensitivity of one micro-strain can be obtained, as can a 0.4 mm spatial resolution for strain measurement. The system can be used for both static and dynamic tests.     

GKJ-1.8m激光自动线位移刻检系统检测长光栅传感器误差分析及评定

对"ＧＫＪ－１．８ｍ激光自动线位移刻检系统"进行了较系统的误差分析,用仪器的系统误差和随机误差合成的方法,评定本仪器测试长光栅传感器光栅位置误差的不确定度．     

Micro-three dimensional shape measurement method based on shadow Moiré using scanning electron microscopy

A novel, precise, three-dimensional shape measurement method using scanning electron microscopy (SEM) and Moiré topography has been proposed. The possibility for measurement of wavelength order using this method is discussed based on results of experiments to confirm the principle. In these experiments, a high-resolution method based on the new measurement method is proposed, employing fringe scanning technology for the shadow Moiré. The optical system is constructed with a SEM using backscattering electrons, a grating holder that can shift the position of the grating, and a grating having a pitch of 120?µm. Measured results using a bearing ball as a sample show that high resolution measurements of around one micrometre can be performed using the fringe scanning method and the new measurement arrangement. An error analysis of the method is performed to enable improvement of the measuring accuracy.     

基于球杆仪和光栅尺的工作台精度调整

用球杆仪和光栅尺同时测量了两轴联动精密工作台的走圆运动．结果显示,光栅尺的主要误差源是测量噪声和定位误差,球杆仪的主要误差源是定位误差．尽管对于单轴实时位置反馈来说,光栅尺的测量精度已经足够,但是两个方向光栅尺的测量数据不能反映两轴间的相对精度．通过对光栅尺和球杆仪测量的工作台走圆运动测量数据的分析,建立了测量系统的数学模型,在此基础上解耦并识别出了球杆仪和光栅尺的定位误差．提出了根据光栅尺倾角误差实现工作台精度调整的策略．     

不依赖于长度基准的光栅细分精度的评定方法

分析了光栅细分精度与利萨如图形的关系，给出了通过利萨如图形评定光栅细分精度的方法。该方法将对测量条件要求极高的细分误差评定工作转化为普通的电压测量和计算，使光栅细分精度的评定不再依赖于高精度的长度基准。该方法适用于各种误差模型的光栅信号，也适用于其它任何以相位差为９０度的两种信号进行细分计量仪器。     

Theoretical error analysis of the sampling moiré method and phase compensation methodology for single-shot phase analysis

Recently, a rapid and accurate single-shot phase measurement technique called the sampling moiré method has been developed for small-displacement distribution measurements. In this study, the theoretical phase error of the sampling moiré method caused by linear intensity interpolation in the case of a mismatch between the sampling pitch and the original grating pitch is analyzed. The periodic phase error is proportional to the square of the spatial angular frequency of the moiré fringe. Moreover, an effective phase compensation methodology is developed to reduce the periodic phase error. Single-shot phase analysis can perform accurately even when the sampling pitch is not matched to the original grating pitch exactly. The primary simulation results demonstrate the effectiveness of the proposed phase compensation methodology.     

伺服电机转子位置检测的误差分析与补偿

针对伺服电机转子位置检测中存在安装不方便、成本高等问题,提出了基于隧道磁阻效应和时栅技术相结合的转子位置检测单元的设计方案。将空间正交的一对TMR传感单元嵌入在电机的前端盖上,实现嵌入式位置精密检测。根据检测单元转子位置解算原理,分析了检测单元的安装误差、电气误差、电磁噪声误差等引起的误差成分。提出了基于超限学习机的误差补偿方法,通过对真实值和测量值样本的训练得到模型最优参数,根据模型参数建立转子位置的误差模型。利用所得到误差模型实现对转子位置的误差补偿。实验结果表明,在2000r/min匀速工况下,补偿前转子位置最大测量误差为4.64°,补偿后转子位置误差为0.315°,精度提升了93.2%,为伺服电机转子位置检测提供了新的方法。     

Optical propagation modified by Cu nanoparticle grating fabricated by heavy ion implantation

The optical propagation property of a planar waveguide with a periodic nanoparticle grating layer is characterized by using sliding prism method. Here, Cu nanoparticle grating was fabricated on a-SiO₂ substrate by periodic heavy-ion irradiation technique. The pitch of these gratings was 2 μm and 3 μm, respectively. The flux and fluence were at the range of 6-10 μA/cm² and 6 × 10¹⁶-1 × 10¹⁷ ions/cm², respectively. The grating effect, mainly including the mode selection effect, is observed. The effect depends on the pitch of the grating and the morphology of nanoparticles. The propagation loss of the waveguide induced by nanoparticle layer is evaluated.