共查询到18条相似文献,搜索用时 125 毫秒
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针对移相干涉仪中移相器的非线性会影响测量结果准确性的问题,提出了一种基于迭代最小二乘拟合的标定干涉仪移相器的新方法。对移相器加电压并采集若干幅干涉图后,通过在帧间和帧内迭代开展最小二乘拟合可计算出干涉图间移相值,从而得出了电压值与移相值的对应关系曲线,通过对曲线作非线性拟合并对电压值进行精密调整,完成移相器的精确标定。在改造后的干涉仪上对此标定方法进行验证,与Zygo干涉仪相比,相同元件下两者测量结果之差的RMS值为1.726 nm。该标定方法可以降低高精度面形测量干涉仪对移相器线性度的要求。 相似文献
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基于统计分析方法的同步移相干涉图位置配准 总被引:2,自引:0,他引:2
使用同步移相干涉仪重建波前相位时,需要对移相干涉图进行准确的位置配准和目标区域确定以保证重建精度和相位解缠绕算法的成功实施。提出一种基于统计分析方法的圆形域同步移相干涉图位置配准技术,对一组包含不同相位分布的干涉图按照对应像素位置进行方差分布函数计算;利用最大组间方差法完成阈值分割,从而分离出干涉图像的背景与目标区域,通过梯度运算检测出目标区域的轮廓;利用改进Hough变换算法估计出各个轮廓的绝对位置和半径参数。数值仿真结果表明,当轮廓半径大于64pixel时,该方法的配准精度可以达到0.5pixel。通过建立自参考同步移相干涉仪对该方法的可靠性与实用性进行实验验证。 相似文献
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针对大口径光学元件干涉测试过程中,测试装置和干涉腔长较大,气流扰动和环境振动对移相测试过程产生影响等问题,采用一种基于二维傅里叶变换的单帧干涉图处理方法,只需要对一幅空间载频干涉条纹图进行处理即可获得待测相位,具有抗振测试的优点。对该方法的基本原理和算法过程进行分析,并对近红外大口径移相平面干涉仪中600 mm口径的光学平晶进行了面形测试。实验结果表明:采用该方法所得波面峰谷值(PV)为0.112,波面均方根值(RMS)为0.014,与移相算法所得波面数据相比,波面峰谷值偏差不到(1/500);波面均方根值(RMS) 偏差几乎为零。 相似文献
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《光学学报》2016,(2)
为抑制动态干涉仪系统中存在的干涉图空间位置匹配误差以及移相误差,采用相位相关算法和载频交叠重构干涉术,前者以光斑边缘为匹配特征,通过配准测试光斑,实现对4幅移相干涉图在空间位置上的像素级配准;后者按列交叠重构4幅载频移相干涉图,实现相位谱与误差谱在傅里叶频谱中相分离,滤取相位谱即可抑制移相误差对测量结果的影响。实验结果显示,两种方法均可以有效抑制干涉图的位置配准误差以及移相量误差,其结果与干涉仪结果相吻合,均方根值和峰谷值分别相差0.0057λ和0.0235λ。相位相关算法不受光强畸变等因素的影响,而载频交叠重构干涉术可以同时抑制由移相器件造成的两倍频相位误差和由光强畸变引入的一倍频相位误差。 相似文献
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为了在飞秒激光抽运-探测(pump-probe)的超快测量中对探针光时间延迟量进行实时检测与有效控制,提出了一种四路同步移相干涉的光学测量系统.应用琼斯理论对该光学测量系统进行了优化设计与计算,推导出同步移相干涉系统各帧干涉图相应点的光强表达式,确定了相邻干涉图之间的相移步长,并给出了相位延迟量测量的解析表达式.最后,对光学系统在检测中可能存在的误差进行了计算分析,结果表明,系统的设计不仅能满足超快pump-probe精度的基本要求,而且优于目前同步移相干涉测量的光学设计,对于800 nm中心波长的探针光在理论上可达阿秒级的时间分辨率.
关键词:
超快抽运-探测
时间延迟量
同步移相干涉
琼斯矩阵 相似文献
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为了实现干涉仪出射准直波前的重构,提出了基于波长调谐移相的横向剪切干涉技术。干涉仪出射波前分别经楔板的前后表面反射,通过角锥棱镜返回后在干涉仪CCD上形成剪切干涉条纹。采用波长移相方法提取剪切干涉条纹的相位信息从而实现准直波前重构。分析相对剪切比对波面重构精度的影响,推导相对剪切比和其影响因素间的关系公式,给出波长移相中光程差常数分量的估算方法。测量干涉仪的三组出射波前,波前的峰谷值分别为3.22λ、2.10λ、0.83λ。该方法简化了传统测量干涉仪准直波前的横向剪切干涉装置,提高了测量精度,特别适合于测量波长移相干涉仪的出射波前。 相似文献
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针对多光束干涉原理的相移算法包括算法误差及步长优化等问题,以菲索干涉仪精密测长为 应用背景进行了研究.利用干涉光学的基本原理导出了在多束光干涉(经光学面多次反射、透 射)的情况下干涉光强随相位分布的精确公式;在此基础上,通过数值分析的方法得出了利 用菲索干涉仪精密测长的相移步长的优化取值范围和干涉光束最佳初相位差的范围;对余弦 依赖算法所引起的光强误差分别就四步法、五步法得出了不同的依赖关系;并对多光束干涉 算法中几种主要的误差来源进行了不确定度评估.
关键词:
相移算法
多光束干涉
精密测长
不确定度 相似文献
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The Jamin shearing interferometer is very useful in wavefront testing, especially for the low coherent light. Based on this interferometer, a polarization phase-shifting Jamin shearing interferometer is proposed to improve the performance. In the interferometer, two interference beams are linearly polarized and a polarization phase shifter is applied to realize the phase shifting. Different types of configurations of the interferometer are given. With phase-shifting interferograms, the precision of the interferometer can be improved. The interferometer is kept as an equal optical path system and its shearing amount remains changeable with simple structure and easy operation. In experiments, phase-shifting interferograms are obtained by rotating the analyzer. The usefulness of the interferometer is verified. 相似文献
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Xiaodong Hu Chunguang Hu Zhi Chen Tong Guo Xiaotang Hu 《Optics & Laser Technology》2007,39(6):1176-1182
A stroboscopic Mirau microscopic interferometer system for measuring in-plane and out-of-plane periodic motions of microstructures is demonstrated. One full cycle of a periodic motion is divided into a number of motion phases. One sequence of interferograms with different phase shifting steps is collected at every motion phase by using stroboscopic imaging. A bright-field image can be extracted from one sequence of interferograms with the same motion phase. In-plane displacements are measured by applying an image matching method to all bright-field images, followed by a compensation for the relative positions of interferograms at the different motion phases, before calculating the phase distribution related to out-of-plane deformation. We demonstrate its capability for measuring a combination of out-of-plane deformation and in-plane displacement in a microresonator. 相似文献
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We revealed that the phase function of a thin-film structure measured by a white-light spectral interferometric technique
depends on the path length difference adjusted in a Michelson interferometer. This phenomenon is due to a dispersion error
of a beam splitter cube, the effective thickness of which varies with the adjusted path length difference. A technique for
eliminating the effect in measurement of the phase function is described. In a first step, the Michelson interferometer with
same metallic mirrors is used to measure the effective thickness of the beam splitter cube as a function of the path length
difference. In a second step, one of the mirrors of the interferometer is replaced by a thin-film structure and its phase
function is measured for the same path length differences as those adjusted in the first step. In both steps, the phase is
retrieved from the recorded spectral interferograms by using a windowed Fourier transform applied in the wavelength domain. 相似文献
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A phase-stepping lateral shearing Sagnac interferometer for wavefront measurement is described. Phase shifting is implemented using a polarisation modulator operating on the wavelength independent Pancharatnam's phase allowing accurate measurement of phase maps even with broadband light. We demonstrate the interferometer by measuring a range of different wavefront shapes using both laser and white light. 相似文献
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The phase-shifting method is all along an important wavefront extraction technique in the interferometer. Moreover, to require almost real-time measurement an algorithm with a small number of grabbed buckets is very helpful to the phase-shifting interferometer. Therefore, those algorithms within five buckets are very practical and are given more attention. In the paper, popular phase shifting algorithms within five buckets are compared and new four and five buckets algorithms are developed to compensate for two dominate error sources which are linear phase shift deviation and detector nonlinearity. Numerical simulations and wavefront extraction experiment verify that the proposed compensation algorithms are insensitive to linear phase shift deviation and detector nonlinearity compared with classical four and five bucket algorithm. 相似文献
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双剪切波面干涉测量法 总被引:7,自引:2,他引:5
用于星间通信的激光器具有接近衍射极限的激光波面,已有的波面测量方法,在这一具体测量问题中,都存在一定限制。双剪切波面干涉测量法在雅满横向剪切干涉仪的基础上,采用四块楔形平板,将干涉图分为上下两个部分,具有不同的条纹间距,由此求出波面高度和符号,同得到单幅干涉图的其它干涉测量方法相比,它的最小可测量波高减小一倍以上。在介绍干涉仪的基本结构和原理的基础上,模拟了像差存在时的干涉图,并在实验上得到了波高为0.3A的初步结果。双剪切波面干涉测量法,可以目视判断波差的符号和估计量值,为等光程相干,适用于半导体等相干长度小的光源。 相似文献