• Title/Summary/Keyword: holographic

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Three Dimensional Shape Measurement of a Micro Fresnel Lens with In-line Phase-shifting Digital Holographic Microscopy

  • Kang, Jeon-Woong;Hong, Chung-Ki
    • Journal of the Optical Society of Korea
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    • v.10 no.4
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    • pp.178-183
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    • 2006
  • An in-line phase-shifting digital holographic microscopy system was constructed by inserting a conventional microscope in the object arm of a Mach-Zehnder interferometer. It was used to measure the three dimensional shape of a micro Fresnel lens. It was also shown that both the lateral and the axial resolutions of the in-line phase-shifting system using a self-calibration algorithm were superior to those of the best off-axis system.

광스캔닝 흘로그래피의 Twin-Image 제거 연산 방식

  • 도규봉
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.196-197
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    • 2001
  • 전자홀로그램(Electronic Holography) 이란 새롭게 고안된 첨단기술로서 종전의 film을 이용해서 3차원 holographic 정보를 기록하는 기술과는 다른 기법으로서, 이 기술은 3차원 holographic 정보를 광학적 시스템과 전자장치를 이용해서 기록하는 기술이다 광스캔닝 홀로그래피(Optical Scanning Holography)란 물체의 3차원 정보를 전자 홀로그램으로 기록하는 전자홀로그램의 기술의 한 방법으로서, 이 기술은 부피가 큰 공간물체의 3차원 정보를 감도의 손실 없이 기록할 수 있으며 많은 응용분야에 성공적으로 상용되어왔다. (중략)

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Modulation Codes for Holographic Digital Data Storage (홀로그래픽 정보 저장 장치의 Modulation 코드)

  • 박주연;황의석;조장현
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.56-57
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    • 2001
  • 정보화의 가속에 따라서, 막대한 정보를 저장하고 처리하기 위한 대용량 정보 저장 장치가 요구되어 지면서, 여러 대응 방법들이 제안되었고, 그중 하나가 HDDS (Holographic Digital Data Storage) 이다. 이는 2차원 페이지 정보를 3차원의 공간상에 저장함으로써 고밀도 저장 능력과 빠른 전송 속도를 실현할 수 있다는 장점이 있다. HDDS는 2차원의 고밀도 이진 영상을 기록하고 재생하는 과정에서 인접 신호의 영향(ISI)과 가우시안 잡음(AWGN) 등이 포함되어지기 때문에 정보 복원 시 에러가 발생할 수 있다. (중략)

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Fabrication and Characteristic Analysis of a Holographic Head-Mounted Display (홀로그래픽 Head-Mounted Display 소자의 제작 및 특성분석)

  • 김희동;정만호
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.200-201
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    • 2001
  • 헬멧 장착형 HMD(Head-Mounted Display) 시스템은 비행기 조종사나 저격수의 시선을 크게 움직이지 않고 군사 전술상의 현재 상태를 볼 수 있도록 하여 눈의 피로감을 줄이고 시선의 이동에 의한 돌발적인 사고의 위험을 감소시킬 수 있어 군사적으로 유용한 장치이다 HOE(Holographic Optical Element)의 중요한 응용 분야 중 하나로 HMD에서의 결상 렌즈 또는 광 결합기가 있다 HMD 시스템에서 HOE의 역할은 2차원의 단색 디스플레이 영상을 헬멧 착용자의 눈에 반사하여 결상시키는 것이다. (중략)

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Holographic nanolithography technique for the fabrication of micro-cavity arrays (마이크로 공진기 어레이 제작을 위한 홀로그래픽 나노노광 기술)

  • Kim, Jeong-Hoi;Kim, Chang-Su;Han, Han-Wook
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.641-642
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    • 2006
  • Two-dimensional (2D) photonic quasicrystals (PQCs) were fabricated by a holographic nanolithography techniques. Using two laser beams with different angles incident on the sample, micro-cavities with 2D internal nanostructures are patterned with a few micrometer periods.

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Omni-directional Tabletop Display Using Holographic Diffusion Screen

  • Fujii, Daiki;Sakamoto, Kunio;Nomura, Shusaku;Hirotomi, Tetsuya;Shiwaku, Kuninori;Hirakawa, Masahito
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1308-1311
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    • 2009
  • The authors describe a 360 degree viewing display that can be viewed from any direction. To generate all-around 360 degree viewing window, we developed a sp ecial diffusion screen with one viewing aperture using holographic optical elements.

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Vortex Ring, Shock-Vortex Interaction, and Morphological Transformation Behind a Finite Cone

  • Jang, Seo-Myeong;Jang, Geon-Sik
    • Journal of Mechanical Science and Technology
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    • v.15 no.11
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    • pp.1599-1604
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    • 2001
  • Axisymmetric compressible flow field induced by shock diffraction from a finite cone is investigated with experimental and computational methods. Double-exposure holographic interferograms show ima ges of the density field integrated along the light path. Using the sight-integrated density based on the Able transformation, the axisymmetric computational results are compared qualitatively with the experiment. In the present paper, we observed some distinguishing flow physics: the fault structure of vortex ring, the shock-vortex interaction, and the morphological transformation of shock waves.

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Holographic femtosecond laser processing

  • Hayasaki, Yoshio
    • Proceedings of the Optical Society of Korea Conference
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    • 2008.07a
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    • pp.61-63
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    • 2008
  • Parallel femtosecond laser processing using a computer-generated hologram (CGH) displayed on a liquid crystal spatial light modulator (LCSLM) is demonstrated. The use of the LCSLM enables to perform an arbitrary and variable patterning. This holographic femtosecond laser processing has advantages of high throughput and high light-use efficiency. A critical issue is to precisely control the intensities of the diffraction peaks of the CGH. We demonstrate some methods for the control of the diffraction peaks. We also demonstrate the laser processing with two-dimensional and three-dimensional parallelism.

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Fractal-space Multiplexing using A Double-Focusing tens (이중초점 렌즈를 이용한 Fractal-space 다중화)

  • Kim, Soo-Gil;Hong, Sun-Ki
    • Proceedings of the KAIS Fall Conference
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    • 2001.05a
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    • pp.277-280
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    • 2001
  • We proposed a novel fractal-space multiplexing holographic memory system using moving window and double-focusing lens, which can eliminate crosstalk due to two neighboring moving window rows in the vertical direction of the conventional moving window holographic memory system, and demonstrated its feasibility through optical experiments.

Experimental demonstration of holographic storage with discrete random phase-code multiplexing

  • Park, Youn-Sup;Shin, Dong-Hak;Jang, Ju-Seog
    • Journal of the Optical Society of Korea
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    • v.4 no.1
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    • pp.43-47
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    • 2000
  • We studied experimentally a discrete random phase-code multiplexing technique for holographic data storage, which we believe can overcome some disadvantages of conventional random phase-code multiplexing adopting either a diffusion plate or a multimode fiber. Experimental demonstration is presented to show the potential usefulness and some characteristics of the discrete random phase-code multiplexing technique.