共查询到20条相似文献,搜索用时 531 毫秒
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JIANG Shiping ZHANG Yuxuan GAO Hongyi ZHANG Xinyi CHEN Min CHEN Jianwen XU Zhizhan .National Synchrotron Radiation Laboratory The University of Science Technology of China Hefei China . Shanghai Ins 《Chinese Journal of Lasers》2001,10(2):127-130
1 Introduction HolographywasproposedbyGabor[1] foraimtoeliminatethesphericalaberrationofelectronoptics.Afterfour yearsBaze[2 ] firstsuggestedGaborholographyforXrayimaging .Howeveruntiltheearly 1 970sAoki,Kikutaandtheircollaborators[3] firstrecordedX rayholograms… 相似文献
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P. W. Wachulak M. C. Marconi R. A. Bartels C. S. Menoni J. J. Rocca 《Opto-Electronics Review》2010,18(1):80-90
Holographic 2D/3D imaging with nanometer resolution using short wavelength extreme ultraviolet (EUV) light is presented in
this paper. Gabor’s holograms were recorded with a highly coherent table top EUV laser with different numerical apertures
demonstrating ultimately a spatial resolution of 46+/−2 nm, comparable with the illumination wavelength, in 2D holographic
imaging. Three dimensional images were obtained from a single high numerical aperture hologram recorded in a high resolution
photoresist and numerically reconstructed at different image planes, allowing numerical optical sectioning with a lateral
resolution ∼170 nm and depth resolution of 2.4 μm. The holograms were recorded in a high resolution photoresist and digitized
with an atomic force microscope. To assess the spatial resolution of the numerical reconstructions of the holograms a correlation
method was used. The algorithm allows for simultaneous estimation of the resolution and the feature size of the image under
analysis. 相似文献
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水窗波段同轴X射线全息成像及其数字重现 总被引:3,自引:2,他引:1
水窗波段同轴X射线全息成像及其数字重现张玉火亘蒋诗平付绍军张新夷(中国科学技术大学国家同步辐射实验室,合肥230029)陈建文徐至展陈敏(中国科学院上海光学精密机械研究所,上海201800)水窗波段软X射线对生物样品成像时,不需要电子显微镜观察时那样... 相似文献
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We report on a technique to recover the spatial resolution of digitally recorded and reconstructed holograms of large objects. Due to the high-contrast speckle noise diminishes the spatial resolution in coherent imaging systems our proposal is based on the reduction of the contrast of it. This aim is achieved through the superposition on an intensity basis of digitally reconstructed holograms of the same static scene. We show a theoretical justification of the procedure and experimentally-obtained results of applying the technique with digitally reconstructed holograms of an object with very poor optical contrast. 相似文献
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Yasuda S Kawano K Minabe J Ogasawara Y Hayashi K Haga K Yoshizawa H Furuki M 《Optics letters》2006,31(17):2607-2609
A technique of recovering the data pages from Fourier holograms recorded without the dc components is demonstrated theoretically and experimentally by use of a coaxial holographic storage system. A reconstructed image is obtained by adding a phase-modulated dc component of the signal beam on reading. The bit error rate of the reconstructed image is comparable with that for the hologram recorded with the dc component as well. Since high intensities of the dc components are not recorded in this technique, the dynamic range of the recording media can be saved, which potentially contributes to increasing the number of multiplexed holograms. 相似文献
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We present a new method for recording digital holograms under incoherent illumination. Light is reflected from a 3D object, propagates through a diffractive optical element (DOE), and is recorded by a digital camera. Three holograms are recorded sequentially, each for a different phase factor of the DOE. The three holograms are superposed in the computer, such that the result is a complex-valued Fresnel hologram. When this hologram is reconstructed in the computer, the 3D properties of the object are revealed. 相似文献
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The results of a theoretical study of the transformation properties of thin dynamic χ(2) holograms for all frequency mixing versions are generalized, and a general pattern of transformations of reconstructed images (recorded and read at different frequencies) is developed. The principles of ray geometric construction of reconstructed images are determined. The theory of thin dynamic χ(2) holograms is extended to the range of third-order aberrations. 相似文献
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Sergio De Nicola Pietro Ferraro Andrea Finizio Giovanni Pierattini 《Optics and Lasers in Engineering》2002,37(4)
Off-axis holograms recorded with a CCD camera are numerically reconstructed in amplitude by calculating through the Fresnel–Kirchhoff integral. A phase-shifting Mach–Zehnder interferometer is used for recording four-quadrature phase-shifted off-axis holograms. The basic principle of this technique and its experimental verification are described. We show that the application of this algorithm allows for the suppression of the zero order of diffraction and of the twin image and that the contrast of the reconstructed images can be further enhanced by digital compensation of the aberrations introduced by the holographic recording system 相似文献
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Color digital holography utilizing the Doppler effect is proposed. The time variation of holograms produced by superposing images at three wavelengths is recorded using a high-speed monochromatic imaging sensor. The complex amplitude at each wavelength can be extracted from frequency information contained in the Fourier transforms of the recorded holograms. An image of the object is reconstructed by the angular spectrum method. Reconstructed monochromatic images at the three wavelengths are combined to produce a color image for display. 相似文献
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A method for fabricating binary amplitude holograms from a dyed photoresist is described. It is of particular interest for holograms that are used as null optics in the form metrology of aspheric surfaces and wavefronts. A pigment that strongly absorbs light near 633 nm was dissolved in a positive photoresist and the dyed resist was spun onto silica glass substrates. Stable resist layers were obtained that were essentially opaque at 633 nm with little effect on the transmittance of the resist in the UV. A Fresnel zone plate was fabricated from the dyed resist layer using contact lithography, and its performance was demonstrated at 633 nm. 相似文献
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H. Rüll 《Optics Communications》1974,11(3):242-244
A report is given on the results of an experiment in which binary data stored in sequentially superimposed one-dimensional holograms with extremely narrow tracks were recorded on a transported recording medium. The width of the holograms was reduced to 3 μm. Since the results obtained show the optical signal-to-noise ratio of the reconstructed image points to be only slightly inferior to that with holograms with 100 μm wide tracks, the method used can be expected to yield an areal bit density greater than 107 bits/cm2. 相似文献
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Controlling image size as a function of distance and wavelength in Fresnel-transform reconstruction of digital holograms 总被引:2,自引:0,他引:2
A method for controlling the size of amplitude and phase images reconstructed from digital holograms by the Fresnel-transform method is proposed and demonstrated. The method can provide a constant reconstruction pixel width in the reconstructed image plane, independent of the recording and reconstruction distance. The proposed method makes it possible to maintain the size of an object for a sequence of digital holograms recorded at different distances and, therefore, to subtract phase maps for an object recorded at different distances. Furthermore, the method solves the problem of superimposition in multiwavelength digital holography for color display and holographic interferometry applications. 相似文献
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Kim MK 《Optics letters》1999,24(23):1693-1695
We propose and experimentally demonstrate a simple digital holographic method that allows reconstruction of three-dimensional object images with a narrow depth of focus or axial resolution. A number of holograms are optically generated by use of different wavelengths spaced at regular intervals. The holograms are recorded on a digital camera and reconstructed numerically. Multiwavelength interference of the holograms results in images of the contour plane whose thickness can be made arbitrarily narrow. Objects at different distances from the hologram plane are imaged clearly and independently, with complete suppression of the out-of-focus images. The technique is available only in digital holography and should have useful applications in holographic microscopy. 相似文献
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模压全息图的颜色设计及其记录方法 总被引:1,自引:0,他引:1
目前模压全息广泛地应用于商品标识、卡通、贺卡等,如何制作出色彩鲜艳、亮度高、清晰的模压全息图是至关重要的。本文从两束光干涉的简单模式讨论模压全息图的颜色设计,给出几种实用的和可能用的浮雕全息图的记录方法,并介绍常用光致抗蚀剂记录材料的特性及其处理工艺。 相似文献
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The first holograms of bubble tracks in a bubble chamber have been recorded. Three-dimensional images have been reconstructed with a resolution of few microns. The technique provides new improvements to the visualization of short-lived particles. 相似文献
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《中国光学快报(英文版)》2016,(6)
An algorithm is proposed for the fast reconstruction of off-axis digital holograms based on a combination of complex encoding(CE) and spatial multiplexing(SM). In this algorithm, every two off-axis holograms recorded in sequence are first assembled into a CE hologram using the CE method, and then four of the CE holograms are again encoded into one complex spatial multiplexing(CSM) hologram based on the SM algorithm. It is demonstrated that the eight holograms encoded into such one CSM hologram can be quickly reconstructed by performing a two-dimensional(2D) Fourier transform(FT) on the CSM hologram. Using this method, the eight 2D FTs required for the reconstruction of the eight holograms in the conventional spatial filtering methods can be simplified to a process with only one 2D FT, which can largely improve the computation efficiency with the 相似文献