共查询到19条相似文献,搜索用时 140 毫秒
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《光学学报》2016,(11)
计算全息元件(CGH)可实现光学非球面的零位干涉高精度检测,但深度非球面的非球面度以及非球面度梯度均较大,使检测所需CGH的局部空间频率偏大,加工困难。提出一种用组合CGH检测深度非球面的方法,该方法通过组合两个低空间频率CGH,实现深度非球面检测时所需的单个高空间频率CGH的功能。由一维线性光栅模型推导组合CGH与传统单个CGH空间频率的关系,并由此给出组合CGH初始相位,逐步优化可求得最佳相位。以最大非球面度193.434μm、最大非球面度梯度75.788μm/mm的深度非球面为测试样例,设计了单个CGH和组合CGH,残留波前误差均小于λ/250,组合CGH最大空间频率约为单个CGH的50%。设计了辅助装调CGH减小装调误差的影响,并分析了组合CGH之间俯仰倾斜偏差、中心偏差以及轴向定位偏差对检测精度的影响。 相似文献
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用计算全息标校补偿器的技术 总被引:3,自引:1,他引:3
用计算全息(CGH)模拟理想非球面主镜的反射波面,用补偿器对该计算全息进行检验,只要计算全息的制作误差能够满足要求,就能实现直接对补偿器的标校。介绍了计算全息标校补偿器的原理、方法,并进行了误差分析。实验采用电子束制作的计算全息实现了对850 mm F/2抛物面主镜补偿器的标校,补偿器产生的标准非球面精度不低于计算全息模拟的主镜面形精度,均方根(RMS)误差为0.012λ。研究表明,用计算全息模拟主镜反射波面对补偿器进行标校是一种行之有效的方法,结合先进的微电子制造技术,可实现对补偿器的高精度标校。 相似文献
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为了标定利用补偿器检测非球面的精度,提出采用倾斜计算全息法(CGH)校验补偿器,并将补偿器精度提高。介绍补偿器检测离轴非球面基本原理,同时结合工程实例,设计补偿器检测860 mm×600 mm的离轴高次非球面,通过加工与装配,仿真分析出装配后的补偿器精度为2.91 nm[均方根(RMS)值]。设计了利用倾斜式的计算全息板检测该补偿器的实验,并分析出利用该CGH校验补偿器的精度为1.79 nm(RMS值)。结果表明,受限于补偿器光学元件加工和组装精度,其检测精度未知,通过对补偿器误差进行检测与标定,可以确定利用该补偿器检测非球面的可行性并将其精度提高。 相似文献
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用双计算全息图检测凹非球面 总被引:9,自引:3,他引:6
为实现对凹非球面的高精度检测,提出并设计了一种二元纯相位型双计算全息图.设计的双计算全息图由主全息和对准全息两部分组成,分别用于检测非球面和精确定位主全息.介绍了双计算全息图的工作原理及其设计方法,并给出了一个检测Φ140、F/2抛物面反射镜的双计算全息图设计实例,实验得到的均方根(RMS)误差为0.062λ.通过分析对准全息的误差,推导出主全息的条纹位置畸变误差,最后计算出其综合误差为0.06A.为验证实验结果的可靠性,将其与平面镜自准直检测结果(ERMS=0.062A)比较,结果二者吻合良好. 相似文献
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《光学学报》2015,(11)
用计算全息图(CGH)检测非球面时,除了设计零位补偿CGH外,还往往设计辅助调节CGH,从而可以利用干涉图来精确调节CGH的位置。针对这种同时具有零位补偿和辅助调节功能的CGH,提出零位补偿CGH和辅助调节CGH之间具有相互补偿效应。针对一高次非球面,设计了四种不同的CGH配置方案,而后逐一分析了零位补偿CGH和辅助调节CGH之间的补偿效应。分析结果表明,在相同的基板误差的条件下,具有自补偿效应的配置方案的Power项误差小于其他方案的1/40,而球差和高阶球差则小于其他方案的1/70。利用具有自补偿效应的配置方案加工制作了CGH,用此CGH完成了对非球面的加工检测迭代,非球面面形的收敛精度均方根(RMS)达到0.48 nm。 相似文献
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Interferometric optical testing using computer-generated hologram (CGH) has provided an approach to highly accurate measurement of aspheric surfaces. While designing the CGH null correctors, we should make them with as small aperture and low spatial frequency as possible, and with no zero slope of phase except at center, for the sake of insuring lowisk of substrate figure error and feasibility of fabrication. On the basis of classic optics, a set of equations for calculating the phase function of CGH are obtained. These equations lead us to find the dependence of the aperture and spatial frequency on the axial diszance from the tested aspheric surface for the CGH. We also simulatethe ptical path difference error of the CGH relative to the accuracy of controlling laser spot during fabrication. Meanwhile, we discuss the constraints used to avoid zero slope of phase except at center and give a design result of the CGH for the tested aspheric surface. The results ensure the feasibility of designing a useful CGH to test aspheric urface fundamentally. 相似文献
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用计算全息(CGH)制作的楔环探测器(WRD)及其在模式识别中的应用 总被引:1,自引:0,他引:1
提出用计算机制全息图配合CCD器件制成具有楔环探测器功能的CGH/WRD系统.它将取样、探测功能相分离,充分利用CGH的灵活性,亦可适用于其他形状的探测.文中详述了系统的设计思想及实现方法并给出了其用于模式识别的实验结果. 相似文献
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Interferometric optical testing using computer-generated hologram (CGH) can give highly accurate measurement of aspheric surfaces has been proved. After the system is designed, a phase function is obtained according to the CGH's surface plane. For the requirement of accuracy, an optimization algorithm that transfers the phase function into a certain mask pattern file is presented in this letter, based on the relationship between the pattern error of CGH and the output wavefront accuracy. Then the writing machine is able to fabricate such a mask with this kind of file. With that mask, an improved procedure on fabrication of phase type CGH is also presented. Interferometrie test results of an aspherie surface show that the whole test system obtains the demanded accuracy. 相似文献
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作为零位干涉检测方法中非常有前途的一种方法.计算全息可以用于非旋转对称的非球面的检测.以三次相位板为例,阐述了利用计算全息图检测非旋转对称的非球面的基本原理.分析并推导了三次相位传播过程引入的高阶波像差的理论公式,给出了三次相位板的检测系统的没计结果.详细讨论了计算全息图衍射级次的分离以及计算全息图的二元化,给出了振幅型的计算全息图的图样.计算全息图的刻线最小问隔是40μm,计算全息图的制作精度对检测结果的波前误差的影响仅仅为0.005λ.对检测系统作了详细的公差分析,结果表明所有调整公差对整个检测系统的影响和方根值为83.954 nm. 相似文献
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为了同时对长焦透镜的面形和焦距进行高精度检测,提出在Zygo干涉仪的球面光路中加入一个二元衍射元件作为检测件的计算全息法。 首先对计算全息法检测长焦透镜的面形和焦距进行了理论推导,并给出焦距误差公式。在Zemax中使用在平面基底上制作的二元衍射元件对一个长焦透镜的面形和焦距进行了模拟检测,其中对该长焦透镜面形的干涉检测PV值为0.0034λ,对焦距的检测精度为-0.11%。最后详细分析了两类误差对检测结果的影响,其中光学元件的位置误差影响不超过0.1λ;二元衍射元件的制造误差影响约0.01λ,在具体制造过程中,其径向位置误差和台阶误差可分别在2 μm和5 nm之内。在综合考虑各项误差的情况下,该方法的检测精度仍然可控制在2λ/25之内。 相似文献
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刘华 《中国光学快报(英文版)》2012,(7):37-40
A convex aspheric surface using a computer-generated hologram(CGH) test plate fabricated with novel techniques and equipment is tested.However,the measurement result is not verified via comparison with other methods.To verify the accuracy of the measurement,a perfect sphere surface is measured by the following.The measurement result is quantified into four parts:the figure error from the tested spherical surface;the figure error from the reference spherical surface;the error from the hologram;and the adjustment error from misalignment.The measurement result,removed from the later three errors,shows agreement to 4-nm RMS with the test by Zygo interfermeter of the same surface.Analysis of the CGH test showed the overall accuracy of the 4-nm RMS,with 3.9 nm from the test plate figure,0.5 nm from the hologram,and 0.74 nm from other sources,such as random vibration,various second order effects,and so on.Thus,the measurement accuracy using the proposed CGH could be very high.CGH can therefore be used to measure aspheric surfaces accurately. 相似文献
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《中国光学快报(英文版)》2017,(11)
The use of a computer-generated hologram(CGH) in interferometric testing provides new methods for highly accurate optical measurement.To fabricate a CGH,polygons are used to approximate the smooth CGH pattern.Because the data size supported by CGH writing machines is limited,the number of polygon vertices must be limited.Therefore,the CGH-encoding method determines the encoding accuracy.To realize a highly accurate optical measurement using CGHs,we propose a CGH-pattern-encoding method based on non-maxima suppression.A self-aligned CGH is designed to verify the accuracy.The experimental result shows that a highly accurate CGH can be fabricated using this method. 相似文献