• Title/Summary/Keyword: digital Hologram

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Effects of the Phase Error on the MTF Characteristics of Binary-phase Hologram Optical Low-pass Filter (컴퓨터로 설계한 2 위상 흘로그램 광 저대역 필터에서 위상차가 필터의 MTF 특성에 미치는 영향)

  • Go, Chun-Soo;Oh, Yong-Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.8
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    • pp.739-746
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    • 2005
  • When we design a binary phase holographic optical low-pass filter (HOLF), the phase difference is generally set to be $\pi$ to optimize the diffraction efficiency. However, the phase difference of real HOLF mostly deviate from $\pi$ by the error in the fabrication process. The deviation causes the (0,0)-th order diffracted beam to increase, which results In raising the diffraction efficiency. To study the effects of the phase error on the performance of HOLF, we calculated the MTF of HOLF for various phase differences. The results show that the phase error of 10 $\%$ makes little change in the filtering characteristics of HOLF. Considering the filtering by lens and CCD, the effects of the phase error becomes much smaller. To confirm it experimentally, we fabricated HOLFs for various phase differences. After installing it in a digital camera, we take picture of test targets and observe the Moire fringes and the resolution. The results agree with our prediction.

Image Stitching and Seamless Holographic Photo-Lithography for Large-Area Patterning (대면적 리소그래피를 위한 홀로그램 영상의 연결과 연결 영역에서의 간섭무늬 제거)

  • Lee, Joon-Sub;Park, Woo-Jae;Lee, Ji-Whan;Song, Soek-Ho;Lee, Sung-Jin;Kim, Oui-Serg
    • Korean Journal of Optics and Photonics
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    • v.20 no.1
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    • pp.23-28
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    • 2009
  • In this study, we propose an image stitching method for large-area holographic photo lithography. In this method, a hologram medium become a hologram mask for lithography. And the mask has information for stitched images. These images are recorded by signal images which are controlled with DMD (digital micro-mirror device), and serial hologram recording is achieved with a motorized linear stage. Using this method, fringe seams appear on the stitching area. To remove these fringe seams, double exposure holographic lithography is tried. Each stitched image is recorded and reconstructed with a different reference beam. The experiments confirm that fringe seams are removed.

Research about digital contents development of internal culture relics (국내 문화유적의 디지털콘텐츠 개발에 관한 연구)

  • Kim, Moon Seok
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.5 no.3
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    • pp.147-154
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    • 2009
  • There are not much digital contents researches that do to culture relics basically. Digital contents research is studied by various method such as Cyber Gallery, 3-D Graphics, Hologram from Scanning that is the simplest form. This research wishes to do with internal culture relics as the central figure that it is that 'Sosu Seowon'. Korean culture contents cyber gallery construction can see as childhood yet. Present result that investigator develops research and as presentation about research process and contents result, wish to argue about problem. Digital contents escapes in existent physical time factor and development to new culture code is possible. Go and come often carrying out and search of fast data or experience of cultural inheritance is available. Through research, wished to present possible metheod actually in digital contents manufacture of internal cultural inheritance. Through this, expect role that offer base in contents manufacture skill.

A study on the Variable Elimination of the 0-th order Diffraction Using the Fourier Transform in the Digital Holography Microscope System

  • Choi, Kyu-Hwan;Kim, Sung-Kyu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1357-1360
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    • 2009
  • In this study, the 0-th order diffraction could be efficiently removed with the obtained data for one hologram using the numerical reconstruction method. This method has a reduced data acquisition and processing time compared with the existing method wherein the data for two or more phase holograms are obtained for regeneration, and efficiently eliminates the 0-th order diffraction.

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Measurement of Highly Aspherical Surface using Computer Generated Holograms

  • Kim, Tae-hee;Choi, Soon-Cheol
    • Journal of the Optical Society of Korea
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    • v.6 no.2
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    • pp.21-26
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    • 2002
  • Interferometric metrology with a null CGH(computer-generated hologram) is presented for measuring highly aspheric surfaces used in a large screen projection television system with high accuracy. The cubic spline surface model which works in a single-pass configuration with a refractive index of object space 0 is used for designing a null CGH. A hybrid null corrector with plano-concave lens in front of a CGH is presented to make the CGH easier to fabricate. Experimental results are presented to demonstrate the validity of the proposed technique.

Elemental Image Synthesis for Integral Imaging Using Phase-shifting Digital Holography

  • Jeong, Min-Ok;Kim, Nam;Park, Jae-Hyeung
    • Journal of the Optical Society of Korea
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    • v.12 no.4
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    • pp.275-280
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    • 2008
  • We propose a method generating elemental images for the integral imaging using 4-step phaseshifting digital holography. Phase shifting digital holography is a way recording the digital hologram by changing the phase of the reference beam and extracting the complex field of the object beam. Since all 3D information is captured by phase-shifting digital holography, the elemental images for any specifications of the lens array can be generated from single phase-shifting digital holography. In experiment, phase-shifting is achieved by rotating half- and quarter- wave plates and the resultant interference patterns are captured by a $3272{\times}2469$ pixel CCD camera with $27{\mu}m{\times}27{\mu}m$ pixel size.