共查询到17条相似文献,搜索用时 187 毫秒
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基于现有的相位空间光调制器,提出并实现了计算机制相位彩虹全息近眼显示.指出带限条件下物光在全息面上相位分布的计算及高频闪耀光栅纵向色散的控制是实现相位彩虹全息的关键要素.在计算相位彩虹全息图时,首先利用带限条件下的角谱衍射算法获取全息面上物光的复振幅分布,并利用双向误差扩散算法将复振幅分布编码为相位分布.然后,对参考光对应的高频闪耀光栅的相位进行编码,得到计算机制相位彩虹全息图.最后,设计了包含白色点光源、准直透镜、空间光调制器、4f滤波系统及目镜的全息彩色近眼显示系统,并通过光学再现获得了相位彩虹全息近眼显示效果,证明了所提方法的有效性. 相似文献
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利用反射全息实现计算全息三维显示 总被引:4,自引:4,他引:0
计算全息和光学全息都可应用于三维显示,但各有自己的优势和缺陷.将计算全息和光学反射全息相结合,可以突破光学全息对记录物体的限制,进行虚拟物体或自然场景的全息图的制作,同时可以实现白光再现.本文首先用三维扫描仪获得实际物体的三维数据,用"点云算法"模拟得到其菲涅耳全息图透射率数据,采用计算全息打印机将其输出于全息记录介质,得到可光学再现的菲涅耳计算全息图H1.然后将H1作为光学全息的记录物体进行反射全息记录,将平面全息转化为体全息,实现了计算全息白光再现. 相似文献
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大景深彩虹全息图的获得与观察条件 总被引:2,自引:1,他引:1
本文从彩虹全息的线状点基元全息图入手,首次对其景深进行了分析和讨论.理论上证明了只要满足一定的观察条件,则彩虹全息可以进行大景深的记录和再现;实验上获得了景深达450mm的彩虹全息图. 相似文献
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一种制作多色彩全息图的新方法 总被引:2,自引:0,他引:2
本文首先提出了一种制作二维透射物彩虹全息图的新方法,即利用一专门设计的全息光学元件──色编码板,采用单光束制作所需物体的彩虹全息图;在此基础上,通过对色编码板的进一步理论设计,制作了一组对应不同主波长的色编码板,实现了记录物体的多色彩虹再现全息图。实验结果表明,此方案简便易行,光路布置灵活性高,且能有效地消除纵向色差的影响,特别适合于模压全息图制造中母全息图的拍摄,并降低了对环境稳定性的要求。 相似文献
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利用数值再现实现彩虹全息色差评价 总被引:2,自引:1,他引:1
为了在计算机制彩色彩虹全息图输出之前定量得到再现像的色彩保真度,提出了一种采用数值再现进行色差评价的方法.首先对彩虹全息图进行了频谱分析,得到再现参量与频谱分布之间的关系;然后采用频域滤波算法实现彩色彩虹全息图数值再现,得到再现像的相对功率谱分布;最后采用CIE1976UCS均匀颜色空间对再现像色差情况进行了计算.设计了7个色块并制作了计算机制真彩色彩虹全息图,以金卤射灯作为照明光源进行了光学再现实验,给出实验结果及分析.研究证明了采用数值再现方法实现对计算彩虹全息再现像光谱分布和色差进行计算分析是一种快速经济的方法. 相似文献
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Fast Computation of Fresnel Holograms Employing Difference 总被引:1,自引:0,他引:1
Hiroshi Yoshikawa 《Optical Review》2001,8(5):331-335
We propose an approximation method that can calculate the Fresnel hologram 16 times faster than the conventional method. To compute the hologram, an object is assumed to be a collection of self-illuminated points and the fringes from each object point are superposed. The distance between object point and sampling point on the hologram is used to obtain the phase of the light. Since a sampled hologram usually has small pixel intervals, the difference of the distance values between adjacent pixels is also small and its n-th order difference can be assumed to be constant. Therefore, the distance value at a certain pixel can be obtained from its neighbor with simple additions. The distance error can be reduced less that one wavelength with practical parameters. A hologram, which has a horizontal parallax only, 1.3 Mega-pixels and 1,000 object points, can be calculated in less than one second with a personal computer. 相似文献
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A simple method of recording full-view rainbow-reflection holograms on a single flat plate is described: only one white-light illuminating source is required in the reconstruction process. The hologram can be viewed from opposite sides, where each side of a three-dimensional object, with its original spatial relationship, is displayed in bright colours. 相似文献
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We proposed a method to solve the problem of extracting meaningful phase information for a single-shot interference pattern taken for an axially tilted fibre sample. Conventionally such interference patterns can be not evaluated with appropriate accuracy. Here, such an interference pattern is considered to be a special hologram since it contains information about light propagated through a laterally fixed sample located at different axial planes. Thus, part of the test object in such a hologram is in focus and the other parts are out of focus. The proposed method can be considered as two complementary steps. In the first step the complex amplitude across the hologram plane is recovered using an adaptive spatial carrier frequency method. This is followed by the second step where the complex amplitude is numerically propagated within a given volume. Thus, planes where the test object is in focus are defined. Consequently, the phase distributions corresponding to all of these planes are together stitched. Thus a complete focus phase map for the fiber sample under test is obtained. From the obtained phase map the two dimensions refractive and the two dimensions birefringence of isotactic polypropylene fibre were calculated. 相似文献
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Xiao-ou Cai 《Optik》2014
As one of the most important 3-D display technique, reduction of speckle noise in the reconstructed image of digital holography should be grounded on the digital hologram itself. Based on the whole process of the recording and reconstruction of digital holography, the optical distributions of recorded object and reconstructed image of digital holography have been studied. It has been proposed that the root formation cause of speckle noise in its reconstructed image is the speckle noise formed on the recorded object surface when illuminated by coherent light because of its optical roughness. A novel approach has been presented to reduce speckle noise in digital holography by changing the interference structure of hologram itself. First, by reducing the speckle noise in the reconstructed image, the distribution of ideal reconstruction light with reduced speckle noise is acquired. Then in turn, taking the ideal reconstruction light with reduced speckle noise as ideal object light, a new hologram can be rebuilt, which can reconstruct the ideal object light. The experimental results are given to confirm the proposed method. Therefore, it offers a brand-new thought and practical way to reduce the speckle noise in the reconstructed image of digital holography. 相似文献
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A new method is investigated for phase-only hologram synthesis. The method combines iterative calculation of the hologram phase function with the coding of the amplitude-phase characteristics of the complex transmission function into phase characteristics. The results of computational experiments are presented. The phase masks and reconstructed object images are also presented. 相似文献