• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.347-348
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• 2006

• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
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• pp.39-39
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• 1997

• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
• /
• pp.3-3
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• 1997

• Proceedings of the Optical Society of Korea Conference
• /
• 1997.08a
• /
• pp.7-7
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• 1997

• Proceedings of the Optical Society of Korea Conference
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• 2002.11a
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• pp.124-124
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• 2002

• Optical Science and Technology
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• v.6 no.1
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• pp.4-12
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• 2002

• Korean Journal of Optics and Photonics
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• v.16 no.5
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• pp.462-468
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• 2005

The bit type holographic data storage is known to have many advantages in instrumentation for its compactness and simplicity, when compared to the 2-D page type holographic data storage. But it requires various multiplexing method for one bit hologram to achieve high storage densities. We propose an optical architecture for bit type holographic data storage which utilizes peristrophic and angular multiplexing simultaneously. Selectivity and characterization are analyzed for the proposed architecture. The possible number of multiplexing(72 bit holograms) and maximum storage densities calculation is confirmed experimentally.

• 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)

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.93-98
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• 2005

Rewritable optical disk is one of the essential data storage media in these days, which takes advantage of the different optical properties in the amorphous and crystalline states of phase change materials. As well known, data transfer rate is one of the most important parameter of the phase change optical disks, which is mostly limited by the crystallization speed of recording media. Therefore, we doped Sn/Bi to $Ge_2Sb_2Te_5$ alloy in order to improve the crystallization speed and investigated the dependence of phase change characteristics on Sn/Bi doping concentration. The Sn/Bi doped $Ge_2Sb_2Te_5$ thin film was deposited by RF magnetron co-sputtering system and phase change characteristics were investigated by X-ray diffraction (XRD), static tester, UV-visible spectrophotometer, electron probe microanalysis (EPMA), inductively coupled plasma mass spectrometer (ICP-MS) and atomic force microscopy (AFM). Optimum doping concentration of Bi and Sn were 5${\~}$6 at.$\%$ and the minimum time for crystallization was below than 20 ns. This improvement is correlated with the simple crystalline structure of Sn/Bi doped $Ge_2Sb_2Te_5$ and the reduced activation barrier arising from Sn/Bi doping. The results indicate that Sn/Bi might play an important role in the transformation kinetics of phase change materials..

• Transactions of the Society of Information Storage Systems
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• v.2 no.1
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• pp.79-84
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• 2006

The next generation of optical storage systems requires higher numerical aperture(NA) objective lenses and shorter wavelength laser in order to improve the unit areal density. A blu-ray technology satisfies a miniaturization and a high capacity which are the requirements of the portable device. In this paper, we analyze the optical performance of hybrid micro lens and do active alignment. The hybrid micro lens is manufactured by using a wafer based fabrication technology. Optical components of hybrid micro lens are evaluated. The measurement of the optical power, the spot size and the wavefront error are performed to evaluate the hybrid micro lens with NA 0.85. Using the measured data, we estimate if the performance of hybrid micro lens corresponds to the designed performance. After the performance of hybrid micro lens is evaluated. the integrated optical pickup and the hybrid micro lens are assembled by active alignment using UV curing and the optical performance of SFFOP is satisfied with BD specifications.