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Surface roughness is one of many parameters that influences on mass stability of standard weight, commonly used as a transfer standard of mass SI unit. One of the most famous non-invasive methods for determining surface roughness from a surface profile of material is a vertical scanning interferometry (VSI) with a white light source. In this research, 3-D surface profiles of 316-stainless steel, usually used as a material for standard weights, are constructed by using VSI, based on Michelson interferometer (MI). Because of its low-coherent properties, low cost, and compact light source, a superluminescent diode (SLD) is chosen as a low-coherence light source in our interferometry system. Since a continuous wavelet transform (CWT) algorithm provides accuracy results, it is also used as a numerical analyzing method for the interferogram signals, taking from our VSI. The surface roughness and measurement uncertainty, calculated from the constructed 3-D surface roughness profiles of 316-stainless steel samples, are discussed. 相似文献
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带侧键的硅氧烷高分子薄膜,在吸收有机分子时它的厚度会发生膨胀,其膨胀幅度与接触的有机物浓度成正比;采用白光干涉测厚的方法可测量出薄膜厚度的微小变化,从而构成一种灵敏的化学一光学传感器。本文介绍了这一新技术及对甲苯,二氯乙烷,三氯乙烷的测量结果。 相似文献
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A combination of thin film colorimetric interferometry and phase shifting interferometry was used to study the effect of slide-to-roll ratio on the micro-elastohydrodynamic action and asperity-contact mechanism on the real asperity scale. The behavior of the roughness features of different scales in very thin film, real rough surface elastohydrodynamic contacts was observed from chromatic interferograms evaluated by thin film colorimetric interferometry. Obtained film thickness distribution was compared with undeformed ball surface topography measured by phase shifting interferometry. It was confirmed that the presence of deep grooves within lubricated contact can result in lubrication film breakdown under positive slide-to-roll ratio conditions when the rough surface is moving slower than the smooth surface. Negative slide-to-roll ratio conditions are much less critical from this point of view. Moreover, shallow pits formed naturally on rubbing surface as a result of surface finishing process were observed to significantly influence the film thickness formation. They act as lubricant micro-reservoirs and emit the lubricant into the contact under rolling/sliding conditions that enlarges film thickness. Such a behavior also suggests the possible beneficial tribological effect of surface texturing based on shallow micro-cavities under mixed lubrication of non-conformal surfaces. 相似文献
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A novel optical fiber sensing system multiplexing low coherence interferometry and high coherence interferometry that is endowed with large range and high resolution and is stabilized for on-line measurement is presented. An optical fiber Michelson interferometer performing measurement task in the system works in both modes of low coherence interferometry and high coherence interferometry simultaneously by employing a broadband light source and a fiber Bragg grating as an in-fiber reflective mirror. The amplitude of the measurand is determined by the low coherence interferometry while the value of the measurand is measured by the high coherence interferometry. Another optical fiber Michelson interferometer which is incorporated with the one performing measurement task stabilizes the sensing system for on-line measurement by exploiting an electronic feedback loop to reduce the influences that are resulted from environmental disturbances. The measurement range is 6 mm and the measurement uncertainty is less than 2 nm. 相似文献
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误差补偿技术在相位偏移干涉测量中的应用 总被引:1,自引:0,他引:1
在研究泰曼—格林相位偏移干涉仪测量原理基础上,分析了位移驱动器移相误差对五幅移相计算结果的影响,一阶线性误差和二阶非线性误差是相位偏移干涉测量技术中产生相位误差的主要因素;提出了五幅算法移相误差补偿技术,该方法直接从相位偏移干涉图中计算移相过程中存在的一阶及二阶移相误差,对五幅算法结果进行误差修正;采用玻璃平晶为测试对象,建立了泰曼一格林干涉仪移相误差补偿原理试验系统。试验结果表明在同时存在一阶移相误差及二阶移相误差情况下,采用提出的移相误差补偿方法可以将位移测量精度提高6倍,相当于采用氦氖激光器的倍程干涉仪中位移精度达到1.0nm。 相似文献
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E. V. Sysoev 《Optoelectronics, Instrumentation and Data Processing》2007,43(1):83-89
A method for measurement of a surface microprofile with a nanometer resolution is described. The method is based on partial scanning of correlograms in a Linnik white-light interferometer. Experimental results on measurements of thin film thickness are presented. It is shown that a depth resolution of better than 1 nm can be obtained by correlogram scanning in the range from 1 to 2 periods. 相似文献
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设计了一种基于迈克耳逊干涉光路的相位测量系统,将单臂作为检测端完成了对玻璃平板厚度均匀性的直接测量和分析。该系统由CCD采集干涉图样,利用傅里叶变换条纹分析术和相位解包裹技术提取干涉图中所包含的待测相位信息;对于傅里叶变换法中频谱旁瓣中心无法准确定位的问题,采用三角变换法去载频,从而不需要准确地得知频谱旁瓣的中心位置就可以计算出相位结果,消除了人为估算和垂轴方向上的微小载频分量给测量结果带来的误差。实验测量了多块玻璃平板的厚度均匀性。测量结果显示:使用像元大小为4.65 μm×4.65 μm的CCD相机,测量玻璃平板两表面在长度方向和宽度方向上的厚度均匀性的理论精度分别达到0.93%和0.92%,表明本系统基本满足玻璃平板厚度均匀性测量的要求,且对干涉图频谱旁瓣的定位精度和载频的方向精度要求较低。 相似文献
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James M. Beach James L. Uertz Lori G. Eckhardt 《Microscopy research and technique》2015,78(10):873-885
A new method of interferometry employing a Fabry–Perot etalon model was used to locate and size microscale features on the surface of the pine bark beetle. Oscillations in the reflected light spectrum, caused by self‐interference of light reflecting from surfaces of foreleg setae and spores on the elytrum, were recorded using white light hyperspectral microscopy. By making the assumption that pairs of reflecting surfaces produce an etalon effect, the distance between surfaces could be determined from the oscillation frequency. Low frequencies of less than 0.08 nm?1 were observed in the spectrum below 700 nm while higher frequencies generally occupied wavelengths from 600 to 850 nm. In many cases, two frequencies appeared separately or in combination across the spectrum. The etalon model gave a mean spore size of 3.04 ± 1.27 μm and a seta diameter of 5.44 ± 2.88 μm. The tapering near the setae tip was detected as a lowering of frequency. Spatial fringes were observed together with spectral oscillations from surfaces on the exoskeleton at higher magnification. These signals were consistent with embedded multi‐layer reflecting surfaces. Possible applications for hyperspectral interferometry include medical imaging, detection of spore loads in insects and other fungal carriers, wafer surface and subsurface inspection, nanoscale materials, biological surface analysis, and spectroscopy calibration. This is, to our knowledge, the first report of oscillations directly observed by microscopy in the reflected light spectra from Coleoptera, and the first demonstration of broadband hyperspectral interferometry using microscopy that does not employ an internal interferometer. Microsc. Res. Tech. 78:873–885, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
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The absolute optical thickness and surface shape of optical devices are considered as the fundamental characteristics when designing optical equipment. The thickness and surface shape should be measured simultaneously to reduce cost. In this research, the absolute optical thickness and surface shape of a 6–mm-thick fused silica transparent plate of diameter 100 mm was measured simultaneously by a three-surface Fizeau interferometer. A measurement method combining the wavelength tuning Fourier and phase shifting technique was proposed. The absolute optical thickness that corresponds to the group refractive index was determined by wavelength tuning Fourier analysis. At the beginning and end of the wavelength tuning, the fractional phases of the interference fringes were measured by the phase shifting technique and optical thickness deviations with respect to the ordinary refractive index and surface shape were determined. These two kinds of optical thicknesses were synthesized using the Sellmeier equation for the refractive index of fused silica glass, and the least square fitting method was used to determine the final absolute optical thickness distribution. The experimental results indicate that the all the measurement uncertainties for the absolute optical thickness and surface shape were approximately 3 nm and 35 nm, respectively. 相似文献
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针对目前相移控制器件费用高、操作复杂等不足,提出了一种数字相移方法.并将其与全息干涉术相结合,进行了相移全息干涉术的实验研究.应用MATLAB软件,结合图像处理方法,通过对全息干涉条纹精确控制使其定向移动,实现了四步相移,获得4个干涉图.应用四步相移法原理和相位去包裹方法,最终成功求得物体变形引起的三维位相差,实现物体变形的三维测试.实验表明,该方法不仅简化了全息干涉测试的光学装置,避免传统相移器件相移精度低、容易造成相移误差的缺点,且操作简单,测试精度高,其精度容易达到1/10波长. 相似文献
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Thin film colorimetric interferometry was used in combination with phase shifting interferometry for the detailed experimental investigation of changes in real surface microgeometry within the elastohydrodynamic conjunction formed between a real, random, rough surface, a steel ball and a smooth glass disc. Three real roughness features were studied in detail — the transverse ridge, transverse groove and longitudinal groove. The ridge was found to be heavily deformed within lubricated contact and its height increased with increasing rolling speed. For the transverse groove, a local reduction in film thickness at the leading edge was observed, while the longitudinal groove maintained its undeformed shape. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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Point contact film thickness in elastohydrodynamic lubrication (EHL) is analyzed by image processing method for the images
from an optical interferometer with monochromatic incident light. Interference between the reflected lights both on half mirrorCr coating of glass disk and on super finished ball makes circular fringes depending on the contact conditions such as sliding
velocity, applied load, viscosity-pressure characteristics and viscosity of lubricant under ambient pressure. In this situation
the film thickness is regarded as the difference of optical paths between those reflected lights, which make dark and bright
fringes with monochromatic incident light. The film thickness is computed by numbering the dark and bright fringe orders and
the intensity (gray scale image) in each fringe regime is mapped to the corresponding film thickness. In this work, we developed
a measuring technique for EHL film thickness by dividing the image patterns into two typical types under the condition of
monochromatic incident light. During the image processing, the captured image is converted into digitally formatted data over
the contact area without any loss of the image information of interferogram and it is also interpreted with consistency regardless
of the observer’ s experimental experience. It is expected that the developed image processing method will provide a valuable
basis to develop the image processing technique for color fringes, which is generally used for the measurement of relatively
thin films in higher resolution. 相似文献
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数字散斑干涉技术可以用来测量物体的微小形变及位移,因其具有较高的精度和全场非接触测量的特点,它被广泛的应用于工业检测、航空航天和生物医学等领域.在该技术中干涉条纹的处理以及相位值的获取是至关重要的.本文介绍了数字散斑干涉技术中条纹处理的各种方法,包括增强、滤波、二值化和骨架线提取等,同时介绍了利用相移技术精确地计算相位... 相似文献
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This article presents an experimental study of the influence of real surface micro-geometry on the film thickness in a circular elastohydrodynamic (EHD) contact formed between a real, random, rough surface of steel ball and smooth glass disk. Phase shifting interferometry was used to measure in situ initial undeformed rough surface profiles, whereas thin film colorimetric interferometry provided accurate information about micro-EHD film thickness behavior over a wide range of rolling speeds. Two real roughness features were studied in detail—a 56-nm-high ridge and a 90-nm-deep groove, both transversely oriented to the direction of surface motion. It was shown that the ridge is heavily deformed in a loaded contact and its height increases with increasing rolling speed. The asperity tip film thickness behavior is quite similar to the contact average film thickness when the film thickness is higher than the undeformed ridge height. However, below this limit the film is thicker than what the EHD theory predicts. For the groove, a local reduction in film thickness at the leading edge was observed. When the groove is passing through the EHD conjunction, it maintains its undeformed shape. The behavior of both roughness features studied shows good agreement with previous experimental observations conducted using an artificially produced ridge and groove. 相似文献
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Jianfei Sun Yonghong Wang Xinya Gao Sijin Wu Lianxiang Yang 《Instruments and Experimental Techniques》2017,60(4):575-583
This paper presents a simple spatial phase shift shearography based on the Michelson interferometer. A novel digital shearography set-up with a large angle of view, which is based on a 4f system is demonstrated. In the system, the Michelson interferometer is used as a shearing device to generate a shearing distance by tilting a small angle in one of the two mirrors. In fact spherical wave fronts become plane after going through the first lens in 4f system. Tilting the mirror in the Michelson interferometer also generates spatial carrier frequency. Sinusoid fitting method is applied to evaluate the phase. This system can generate a phase map of shearography by using only a single image. The effects of shearing angle, the choice of algorithm and comparison result are discussed in detail. The theory and the application are presented. 相似文献