• Title/Summary/Keyword: localized hologram

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Overlap properties of reference beams far localized recording of neighboring holograms (이웃한 국소 홀로그램 기록을 위한 기준빔의 겹침 특성)

  • 오용석;김복수;장주석;김지덕;이홍석
    • Korean Journal of Optics and Photonics
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    • v.14 no.1
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    • pp.65-71
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    • 2003
  • To maximize the storage density in a localized hologram recording method, each hologram should be recorded as close as possible to its neighboring holograms. In this case, the reference beams used to record two adjacent holograms may overlap in spatial multiplexing. Through simulations and experiments, we show that there exists an optimal reference beam size to minimize the overlap for a given shifting distance of the reference beams in spatial multiplexing. Thus the advantages of the localized hologram recording method can be minimally sacrificed while the storage density is increased.

Holographic disk memories based on localized hologram recording (국소 홀로그램 기록방식에 기초한 홀로그래픽 디스크 메모리)

  • 오용석;김복수;장주석;강영수
    • Korean Journal of Optics and Photonics
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    • v.14 no.6
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    • pp.663-668
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    • 2003
  • We studied a localized hologram recording method that can be used in a disk-shaped medium. In this method, the reference beam is focused by use of a cylindrical lens to get a thin spot in the medium, and then a hologram is recorded in that spot by illuminating the signal beam. Many localized holograms are multiplexed by shifting the medium by a distance more than the thin spot size of the reference beam. This method does not need recording-time scheduling for uniform diffraction efficiencies. We show that a minimal required thickness of the recording medium exists for a given spot size of the signal beam. We performed experiments for data storage and retrieval, and obtained a storage density of 20 bits/${\mu}{\textrm}{m}$$^2$ and a raw-bit error rate (RBER) of 2.5${\times}$10$^{-3}$ , when a 2 mm-thick Fe-doped LiNbO$_3$ crystal was used.

Digital Hologram Coding Technique using Block Matching of Localized Region and MCTF (로컬영역의 정합기법 및 MCTF를 이용한 디지털 홀로그램 부호화 기술)

  • Seo, Young-Ho;Choi, Hyun-Jun;Kim, Dong-Wook
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.415-416
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    • 2006
  • In this paper, we proposed a new coding technique of digital hologram video using 3D scanning method and video compression technique. The proposed coding consists of capturing a digital hologram to separate into RGB color space components, localization by segmenting the fringe pattern, frequency transform using $M{\tiems}N$ (segment size) 2D DCT (2 Dimensional Discrete Cosine Transform) for extracting redundancy, 3D scan of segment to form a video sequence, motion compensated temporal filtering (MCTF) and modified video coding which uses H.264/AVC.

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