共查询到20条相似文献,搜索用时 93 毫秒
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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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《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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Ting-Chung Poon 《中国光学快报(英文版)》2009,(12):1065-1065
This focus issue Digital and Computer Generated Holography (DCH) combines the contributions from digital holography (DH) and computer-generated holography (CGH) into a single issue. We have classified the papers into four topics: holographic microscopy, computer-generated holography, 相似文献
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微光成像系统的阈值探测理论和视距探测方程的研究(续)艾克聪(四安应用光学研究所710100)3实际成像系统探测方程的研究和分析为了克服理想成像系统探测方程存在的局限性和不足之处,许多专家学者对其作了进一步的深入研究,提出了各种不同的改进和修正意见,以... 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 low risk 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 distance from the tested aspheric surface for the CGH.We also simulate the optical 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 surface fundamentally. 相似文献
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对用于超大规模集成电路光学互连的计算机制全息图(CGH)的量化噪声及取样影响进行了分析.CGH透过率函数的二值化将带来一些噪声,但仍可得到高的信噪比.在光学互连CGH的结构是菲涅耳波带片的条件下,对Nyquist和Whittaker-Shannon两种取样方法进行了分析和比较.结果表明,在小偏转角和高取样频率条件下,用Whittaker-Shannon取样方法得到的衍射效率比用Nyquist取样方法所得到的衍射效率大. 相似文献
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A Lohmann-type computer-generated hologram (CGH) is fabricated using an electron-beam lithographic system. A high-resolution
groove width of 0.2 μm is attained in relief gratings by changing the e-beam exposures. A diffraction efficiency close to
∼30.4% is obtained by using resist-on-silicon recording materials and cell-structural apertures in a CGH. The reconstructed
images exhibit fewer phase noises owing to the incorporation of a non-overflow cell structure into a CGH. The CGH is designed
for reconstruction-noise reduction by using an iterative error-reduction algorithm. The designed CGH exhibits fewer reconstruction
noises such that the performance function in the convergence is smaller by a factor of 1/3 than that in the first iteration.
Experiments demonstrating the performance of CGHs obtained by electron-beam lithography are presented. 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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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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A method of simulated annealing in optimization of a computer generated holo-gram(CGH)is presented.The characteristics of energy in annealing curve are analyzed.Thecooling schedule such as giving an initial temperature,the temperature function,the numberof interactions and stopping criterion are discussed.As an example,an optimization of phaserelief kinoform,a CGH with multiple phase levels,is implemented. 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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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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Rahul Bhatt Sanjay K. Mishra D. Mohan A.K. Gupta 《Optics and Lasers in Engineering》2008,46(6):428-439
A fast holographic wavefront sensor is proposed using a computer-generated hologram (CGH). This CGH is a multiplexed hologram of different Zernike mode–amplitude combinations, and is designed in such a manner as to get the corresponding spots on the detector according to the presence and strength of a particular aberration. Interference between the aberrated wavefront (with a single mode–amplitude combination) and the Fourier transform of an image with single bright pixel (defined as dot image) is numerically calculated for one hologram. Different mode–amplitude combination and corresponding different positions of bright pixels (dots) are taken to compute various holograms and then all the holograms are multiplexed to get the final hologram. When the aberrated wavefront with a particular mode–amplitude combination is incident onto the multiplexed hologram, the corresponding dot is generated in the Fourier plane. A lens performs the Fourier transform in optical domain and provides the instant detection of amplitude of the respective Zernike mode. The main advantage of the scheme is to avoid the need of any computations, which makes it really fast. The simulation results are presented with the cross-talk analysis for few Zernike terms. 相似文献