用RSP—Ⅰ型全息干版做光学全息演示实验

采用新型红敏光致聚合物全息干版拍摄全息图,在日光灯下操作,实验过程观察得清楚;位相型全息图的处理方法简单;重现的全息像效果明显:具有高亮度、高清晰度、极强的立体感,强烈的艺术效果.     

明室全息照相技术

本实验采用SRP—I型红敏光致聚合物干版,在明室条件下对反射式全息图的拍摄过程及条件进行了研究。     

垂直分割视场制作合成动态全息图

从理论上及实验上分析了利用垂直视场分割法制作合成动态全息图的方法。将二步彩虹全息术中的主全息图Ｈ１分成若干全息单元,在各单元中分别记录了物体一系列连续变化状态的二维图像,利用该主全息图制作像面全息图Ｈ２,从而获得合成动态全息图。该方法用银盐干版记录主全息图Ｈ１,节省了大量的曝光时间。     

大尺寸物体彩色全息图制作的研究

通过分析两步法制彩色全息图中全息图空间带宽积与物体大小、全息图记录距离的关系,提出了一种拍摄大尺寸物体彩色全息图的方法。经编码,设置参数,在视窗处平面记录下三分色全息图, 以保证用最小的幅面记录下物体的完整信息,并且H1rgb处于同一平面经原参考光的共轭光再现时,他们的再现像能完全重合;将H1rgb再现,获得大视场的物光波信息,三基色物波信息重合后,用光学方法记录大幅面的彩色全息。该方法能提高全息图再现像的视场和解决大尺寸物体的全息图难拍摄问题。 经实验验证,该方法能将全息图再现像的视场提高6倍左右。     

激光全息照相实验探讨

1962年由杰尼休克提出的反射全息图的制法至今还是实验教学的一个内容。本文介绍对干版仅仅曝光一次的条件下,将白光反射再现全息图和激光透射再现全息图同时记录于同一干版上的实验。由此得到的全息照片不仅可在白光下再现。而且可在激光下再现,且两次再现的像既可相同也可不同。图1为实验光路图。如将图中物Ⅱ去掉,该图即变成记录激光透射再现全息图的光路;而将物     

三维动画显示体积全息图的研究与制作

根据体积全息图的角度复用特性,在一张卤化银干版上记录了多幅图像,再现时轮流显示不同画面从而实现动画显示的效果。设计记录波长632.8nm,再现波长532nm。通过记录和检测光栅确定全息图的处理工艺,从理论上分析了因乳胶收缩导致的光栅结构变化问题,计算得到全息图的记录和再现条件,消除了再现像"左右跳动"的现象,在一张干版上记录了4幅子图。设计并制作完成了自动控制电路和展示装置,实现了三维动画显示效果。     

利用氯化银强光分解银提高全息图衍射效率

本文提出将银盐振幅型全息图先漂白成氯化银全息图,再经强光照射转变为银微粒位相型全息图的光分解银方法.用天津I型全息干版,衍射效率可达28%,并对光照稳定.电子显微镜照片显示出光解银的线度为0.01μm数量级,从而解释了本方法提高衍射效率的原因.     

一种制作多色彩全息图的新方法

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。     

关于改善彩色全息图色饱和度的处理工艺研究

本项目采用俄国PFG－03C新型全色超微粒银盐干版作为记录材料,通过控制三原色激光曝光的色平衡比,优化改进显影、漂白等后处理配方及步骤,制作出色饱和度好、衍射效率高、信噪比高的彩色全息图。实验测试结果表明,我们的处理工艺比国外报道的结果好,可以有效地抑制乳胶收缩及由此带来的再现波长漂移、全息图像色饱和度降低等关键性问题。     

用国产全息干版提高全息图衍射效率

本文提出一种新颖的显影液配方及漂白处理工艺。通过此工艺过程得到的位相型全息图银盐微粒细而密,折射率变化明显,全息图的衍射效率得到了提高。用国产天津Ⅰ型全息干版,衍射效率可达29%。     

Real-time color holographic interferometry devoted to 2D unsteady wake flows

A new optical technique based on real time holographic interferometry in true colors has been implemented around the transonic wind tunnel of the ONERA-Lille center to analyze 2D unsteady wake flows. Tests realized in color interferometry, real time and double exposure, use simultaneously three wavelengths of a continuous waves laser (argon and krypton mixed) and holograms are recorded on silver-halide single-layer panchromatic Slavich PFG03c plates. The very principle of real-time true color holographic interferometry uses three primary wavelengths (red, green and blue) to record, under no-flow conditions, the interference among the three measurement beams and the three reference beams simultaneously on a single reference hologram. After the holographic plate is developed, it is placed on the test setup again in the position it occupied during exposure and the hologram is illuminated again by the three reference beams and three measurement beams. A flat, uniform color can then be observed behind the hologram. So a horizontal, vertical, or even circular fringe pattern can be formed and the achromatic central fringe can be made out very clearly. The single color is used to determine the path difference zero on the interferograms. The flow studied was the unsteady flow downstream of a cylinder placed crosswise in the test section. A sequence of hundred interferograms was recorded on the flow around the cylinder at Mach 0.37. The vortex formation and dissipation phases can be seen very clearly, along with the fringe beat to either side of the cylinder.     

Control of the Rendition Wavelength Shifts of Color Lippmann Holograms Recordedin Single-layer panchromatic Silver-halide Emulsion

1 Introductionther hologratns can be used for artWork fabrication, product advertisement,museum item presentation, etc., and have wide applicationS in the world of businessand everyday life. To be able to record high-quality color reflection holograrns, it isnecessary to use extremely low scattering recording materials, for example, the use ofultra-high resolution silver-halide emulsions. Russian PFG-03C panchromatic silverhallde Plate is such a recording material, which has some excellent c…     

Control of the Rendition Wavelength Shifts of Color Lippmann Holograms Recorded in Single-layer panchromatic Silver-halide Emulsion

Russian PFG-03C panchromatic ultra-high resolution silver-halide emulsion is regarded as the most successful material for the fabrication of color reflection holograms. But the lack of established and reliable processing sequences prevents its practical applications in business and everyday life. Though much attention is drawn upon the processing of PFG-03C color reflection holograms, the color desaturation is still a problem. The article describes the new processing of color holograms recorded in PFG- 03C plates which is demonstrated experimentally to have the capacity of controlling the rendition wavelength shifts and improving the color desaturation effectively. The rendition spectra of Red-Green-Blue (R. G. B. ) single-line reflection holographic gratings, and the color reflection hologram as well, are given in this paper.     

Hologram recording in DuPont photopolymer films by use of pulse exposure

Reflection hologram recording in DuPont HRF-800X071-20 photopolymer films has been demonstrated by use of pulsed laser exposure with pulse lengths of 25 ns. An expected weak reflectance of the recorded mirror holograms could be significantly increased by preillumination. Although pulsed preillumination enhanced only the reflectance, continuous incoherent preillumination significantly increased both the diffraction efficiency (which reached ~80%) and the sensitivity (which reached an increase of ~100 times, thus approaching the sensitivity of cw recording). The results are compared with those for hologram recordings obtained with cw exposure under the same processing conditions. Spectral absorbance curves of recorded holograms are presented, and possible mechanisms of hologram formation are discussed.     

Full Color Computer-Generated Rainbow Hologram with Enlarged Viewing Angle

The viewing angle of a computer-generated hologram (CGH) can be expanded by lens-less Fourier configuration. However, a laser is required to illuminate the CGH for reconstruction. We proposed earlier making a second hologram for white-light reconstruction; here, we propose a method to calculate CGH for a full-color rainbow hologram with enlarged viewing angle. First, we calculate the master hologram with three virtual slits whose positions correspond to red, green and blue wavelength. The transfer hologram can be made from the master CGH with a single exposure. In the experimental result, we obtain a full-color computer-generated rainbow hologram with 17° of viewing angle and 3.0mm × 2.5 mm image size.     

一种普适型国产银盐感光胶的全息特性实验研究

实验研究了一种普适型国产HR_1型卤化银乳胶的主要全息特性;论述了其曝光量对衍射效率的影响;比较了两种化学后处理方法对衍射效率和信噪比的影响。实验结果表明,HR_1型卤化银乳胶是一种适合于记录透射和反射型合成全息图的记录介质,可以获得较高的衍射效率和信噪比。     

Dependence of the profile of a hologram recorded on color centers in a CaF2 crystal on the type of hologram-forming centers

A hologram recorded in a CaF₂ crystal by modulating the concentration of simple centers (F, M, R, and N) and highly aggregated (mainly colloidal) color centers has been exposed to incoherent 365-nm light to a dose of about 4000 J/cm² at a temperature of 80°C. As a result of this exposure, the color centers were almost completely transformed into quasi-colloidal centers. The hologram was retained, and its diffraction efficiency increased; the intensity and number of observed diffraction orders increased as well. Analysis of the angular dependences of the diffraction response made it possible to construct a spatial profile of the hologram, which turned out to be much narrower in comparison with the initial-hologram profile; both profiles differ from a sinusoidal one. The hologram??s stability to such a large exposure to incoherent light at an elevated temperature is related to the peculiar diffusion-drift mechanism of hologram recording on color centers in ionic crystals.     

Application of interference microscopy to the study of hologram build-up in LiNbO3 crystals

Interference microscopy was applied to direct microscopic observation of temporal evolution of phase holograms in LiNbO₃:Fe photorefractive crystals. First a hologram was recorded in the sample, and diffraction efficiency was monitored during hologram build-up using inactinic laser light. Thus kinetics of hologram build-up could be determined. The initial hologram was erased using white light. Then a series of write-erase cycles were performed with increasing exposure times. Holograms were observed by interference microscope after each exposure. The time elapsed between the exposure and the microscopic observation was negligible compared to the relaxation time of the hologram. The obtained temporal evolution of the grating profile gives a deeper insight into the physical mechanism of hologram formation in photorefractive materials than simple diffraction efficiency measurements. A congruently grown sample of LiNbO₃ doped with 10⁻³ mol/mol Fe in melting was studied by this method. Sample thickness was set to 300 μm to allow correct microscopic observation. Plane-wave holograms were recorded in the samples using an Ar-ion laser at λ = 488.0 nm of grating constants of 3, 6.5 and 8.8 μm.     

三维漫射体单波长真彩色彩虹全息术

提出一种新的三维漫反射物体真彩色彩虹全息术,在普通一步法真彩色彩虹全息术的基础上,用单波长激光逆光路再现,可在同一种记录介质上一次曝光记录三维物体的真彩色全息图.因而特别适合于制作光致抗蚀剂模压全息母板.     

A method of making a true color stereoscopic hologram

A true color stereoscopic hologram is made with one-wavelength laser. Under illuminating incandescent lamp, a true color stereoscopic image can be seen from the hologram. A diffused reference light and a project object light are used in the recording of the hologram. The three primary color images of natural scenery are encoded on a white-and-black film. With the help of the encoded film, a true color hologram is recorded on a plate by single exposure and a true color stereoscopic by two exposures. The simplification of this method is apparent. Further more, it largely decreases the scattering noise of the hologram and averts the problem of color lack fidelity of the holographic image.