真彩色体视全息图

用三色光栅照相机拍摄景物的两张视差照片,然后用单色激光器经二次曝光全息记录制成一张真彩色体视全息图,在普通白炽灯照明下可再现真彩色体视全息像.该方法制作过程更简单,减少了散斑噪音,消除了彩色全息像的色差,得到的全息像清晰明亮,色彩真实,立体感强.     

真彩色全息图的制造新方法

提出采用特殊制作的色编码板，结合空间分离取样技术及彩色荧光屏发光混合原理和方法，仅用单束光，制造一般二维物体的真彩色全息图，文中还叙述对掩膜的制作方法，及高质量色编码板的参数选取和制备方法。最后给出了实验结果。     

二维真彩色全息图的研究

章提出了一种新的利用光信息处理系统和彩虹全息技术相结合的二维真彩色全息实现方法。     

真彩色彩虹全息图图像合成技术

介绍了真彩色虹全息图图像的合成技术，讨论了合成的记录光路和两个物体的相对位置随Ｈ１的记录光波长而变化所应满足的关系，以防止两个物体的再现像因错位而发生互相干扰的现象。     

模压全息图的再现过程

本文就模压全息图的再现过程进行了论述。由于模压全息图的特殊性，本文论述了模压全息图再现时的一些现象，这对于设计２Ｄ／３Ｄ模压全息图有一定的参考意义。     

实用的三维真彩色模压全息

三维真彩色模压全息图从艺术角度、信息量、技术含量和防伪功能均优于平面假彩色和平面真彩色模压全息图。本文分析了拍摄三维真彩色彩虹全息图的原理,给出了本方法实现实用三维真彩色模压全息的特点。     

利用光致聚合物的真彩色反射全息图

本文用Ar~+-Kr~+激光器的红光(647.1nm)、绿光(574.5nm)和蓝光(488.0nm)分别对准全色的光致聚合物干板制作反射光栅,给出各个反射光栅的光谱透射率曲线,由此可得最小透射率随曝光量、再现波长随曝光量变化的情况.并采用Ar~+-Kr~+激光器全谱线输出和减色滤光片一次曝光成功地拍摄了真彩色反射全息图.本文还讨论了彩色反射全息图再现像的色度坐标和彩色控制.     

大视角真彩色全息图制作的新方法

为了提高全息图的彩色效果和增加其视角,结合光学全息和计算全息的优点,利用镜像法提出了一种提高全息图彩色效果和增大视角的新方法。制作方法分两步来实现,第一步,镜像迭加的分色计算全息图H1r,H1g,H1b的制作。第二步,利用光学的方法制作彩虹全息图H2。设计光路使再现的光波经平面镜反射,按光的可逆原理展开,形成大视角再现。经理论分析和实验验证,实验获得的全息图可以在大视角(约14°)情况下观察到彩色再现像,彩色效果和立体效果均较为明显。     

透射/反射型模压全息图

<正> 传统的模压全息图采用镀铝PET或烫印箔作工作介质,再现像的视场角受到全息图衍射和色散的限制。在有效衍射范围之外,再现像消失,只能观察到由镀铝层的镜面反射形成的银白色的视场。对低衍射效率的全息图,这一问题尤为突出。由于寻找图像比较困难,造成了目前许多用户对全息防伪商标的疑虑。透射/反射型全息图以一个独特的角度解决了上述问题。     

模压全息图母版的拍摄研究

目前拍摄模压全息母版用的记录材料都是光刻胶.本文从它本身的特点(灵敏度低,浮雕型相位光栅和拍摄对象是散射物体等)出发,指出要拍摄出质量好的光刻胶母版应当注意到的问题.诸如拍摄参数的选择应同时考虑到衍射效率和信噪比、照明的均匀性问题、逆共轭光再现、消偏振、相干长度、外界振动对拍摄的影响问题.通过分析表明高质量的全息图不可能靠延长曝光时间来获得,使用相干性好的大功率激光束来拍摄,是非常有必要的.     

Hologram recording

Parallelism is an intrinsic feature of many physical systems. The design of high-performance computers is increasingly making use of this concept by employing many processors working co-operatively to carry out a single computation. Consequently, the computer simulation of physical systems can rather naturally exploit the latest computer architectures to test theoretical models and to make measurements that are inaccessible to real experiments. In this article we review the design and use of parallel computers. In a subsequent article we will describe how they have been used to obtain insight into some fundamental problems in physics.     

Parameter Dependence of the Iterative Stepwise Quantization Method in Hologram Binarization for Real and Complex Amplitude Signals

In this paper we present the results of parameter dependence analysis of the iterative stepwise quantization method in amplitude hologram binarization. Although the original method considers only a real amplitude signal, we also analyze the parameter dependence for the complex amplitude signal. The results of the analysis help in selecting the parameters in a way that binary holograms with improved quality of reconstructions can be obtained.This paper was originally presented at the 2nd International Conference on Optical Design and Fabrication, ODF2000 which was held on November 15-17, 2000 at the International Conference Center, Tokyo, Waseda University, Japan.     

Optimization of Binary Hologram Degraded by Periodic Lattice Structure of Liquid-Crystal Device Panel in Real Optical Security Systems

A numerically generated encryption pattern in practical optical security systems is processed through real display devices such as electronically addressed spatial liquid-crystal devices (LCDs). The pattern to be encrypted must be therefore congenial with electronic interfaces. In usual fact, the quality of a decrypted image in a practical system is greatly degraded due to the mismatch between the desired encryption pattern and the generated pattern without consideration of the device structures, such as lattice structures of LCDs. We take into account lattice structures for the displays of encryption and key patterns in real optical security systems and apply a simulated-annealing like method for the optimization of an encrypted binary hologram. We successfully demonstrate the decryption of holograms by this method.     

Computer Generated Rainbow Hologram

The rainbow hologram is very practical to display 3-D images because it can be reconstructed with white light. We propose a simplified model to calculate the computer generated rainbow hologram quickly. In the proposed method, we can simply generate the final hologram from intermediate data, whose total number of samples can be less than one tenth of the final hologram. This intermediate format makes fast computation and effective storage/transmission possible. Only multiple and additional operation need be used to convert the intermediate data to final data. Therefore, it is possible that hardware can be added to an electro-holographic display or printer. In this paper, we discuss both theory of the simplified model and experimental results of white light reconstructed images. Full color holograms are also discussed.     

全息图的数字重现

计算机数字重现全息图可消除像差，噪声及记录过程中底片非线性因素的影响，与可见光重相现比有更大的灵活性。对短波和全息如Ｘ射线全息，电子全息来说，数字重现可大大提高其重现分辨率。本文给出了全息图数字重现的理论公式，利用理枋全息图的强度分布数据成功地重现了同轴和离轴全息图，并对重现结果作了分析。     

闪耀型彩虹全息术

彩虹全息术中的长狭缝演化为一个点，可极大提高再现像的亮度，文中阐述了这种闪耀型彩虹全息图制版光路，论证了在明视距离处形成出射瞳孔实像的条件，指出了这种多色显示的全息图有高信噪比。     

矩形带通反射全息的实验研究

矩形带通反射全息在一定带宽内（约１０～２０ｎｍ）具有极高的衍射效率，在反射全息的应用中具有特殊的意义，本文给出了这一反射全息的制作了工作过程和实验结果，实测结果表明对于两类矩形通反射全息，衍射效率分别达９９％和９５％以上，峰值带宽大于１０ｎｍ。     

Hologram multiplexing in acrylamide hydrophilic photopolymers

Unslanted diffraction gratings are recorded in a 900 μm thick acrylamide photopolymer by means of peristrophic multiplexing. A solid state Nd:YAG (λ = 532 nm) laser is used as the recording beam, with a total incident intensity of 5 mW/cm², and a He-Ne laser as the reconstruction beam. The dye concentration in the photopolymer is optimized so that it does not limit the dynamic range. Nine holograms are recorded using constant exposure time scheduling and variable exposure time scheduling. From the results obtained it may be deduced that optimization of the dye allows us to work in the linear response region of the photopolymer and at the same time obtain high values of diffraction efficiency for each hologram. An exponential increase in exposure time as the number of holograms increases enables the values of diffraction efficiency to be homogenized with regard to the case of constant exposure scheduling. In this way, better use is made of the dynamic range of acrylamide hydrophilic photopolymer.     

全息实验的新研究

介绍了全息干板经过一次曝光后,不但在原位置再现两个探索像,而且发现经过旋转干板,还可以再现另外两个放大倒立的像的过程。