• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.262-263
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• 2002

오늘날 정보화 사회가 세계적으로 구축됨에 따라 초고속 광네트워크 사이의 통신용량의 급격한 증가로 인하여 대용량의 정보를 초고속으로 처리할 광스위치의 필요성이 심각하게 대두되고 있다.[1] 현재 연구되고 있는 광스위치 중에는 광도파로 형테와 MEMS형, 기계식 형태가 있다.[2] 그러나 이들 형태의 광스위치는 대용량과 초고속이라는 두 개의 기능을 동시에 수행하기에는 기술적 어려움이 있다. (중략)

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.862-863
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• 2006

According to the experiment results, the alignment of FLC cell can become more uniform at thick cell gap by adjusting the amplitude of the aligned AC electric field which is applying to the FLC cell during $N^{\ast}-SmC^{\ast}$ phase transition. If the amplitude of AC electric field is high enough, the FLC molecules forced with the amplitude and aligned to a particular direction.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.571-574
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• 2002

We propose modified concept that enables LCDs quasi-impulsive operations, and demonstrated a prototype AM-LCD that is suitable for displaying moving pictures combined with '2-Domain Half-V shaped switching mode' FLCD.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.910-913
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• 2002

We have achieved an improved stability of an analog electro-optic effect in FLC/polymer composite films. The optimization of device depends on both the composition of the FLC/polymer mixture and the energy of UV irradiation. This device exhibits continuous gray scales and the mechanical stability against external forces.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.112-113
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• 2003

광통신 시스템에는 다양한 광소자들이 삽입되어 사용된다. 특히 보다 많은 정보의 전송을 위하여 WBM 소자들이 흔히 사용되고 있다. 이와 같이 data 처리용량 및 속도 증가에 대응하기 위한 광섬유의 개발이 활발하게 연구되고 있으며 data 전송용량이 증가되면 channel 파장 대역폭이 좁아지게 되고 전송 속도가 증가되면 색분산 등 광섬유의 비선형성에 의한 영향이 크게 나타나게 된다. 또한 장거리 통신망 등에서는 온도 변화에 의해 분산 기울기 변화가 전송 제한 요인이 된다. (중략)

• Korean Journal of Materials Research
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• v.4 no.6
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• pp.695-703
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• 1994

Some 4-(4-alkyloxybenzoyloxy)-4'-(S)-$\alpha$-chloro-alkanoyloxybiphenyls have been synthesized and their mesomorphic properties were studied. They show a ferroelectric chiral smectic C phase in addition to the chiral nematic and smectic A phase. We obtained a large spontaneous polarization exceeding $10^{-7}\textrm{cm}^2$ in new biphenyl ester series.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.476-479
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• 2005

We developed a plastic bistable LCD based on the suspension of sub-micron ferroelectric particles in a cholesteric liquid crystal. 2.5 inch $160{\times}160$ pixel display with enhanced contrast and improved electro-optical characteristics was achieved. The display is extremely light and possesses good flexibility, demonstrating multifold bending in a radius about 1.5 cm.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.445-448
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• 2002

New banana-shaped achiral compounds, 1,3-phenylene bis [4-{4-(7-octenyloxy)phenyliminomethyl}benzoate](PBOEB), 1,3-phenylene bis [4-{3-fluoro-4-(7-octenyloxy)phenyliminomethyl}benzoate] (PBFOEB), 1,3-phenylene bis [4-{4-(10-undecyloxy)phenyliminomethyl}benzoate](PBEUB), and 1,3phenylene bis [4-{3-fluoro-4-(10-undecyloxy)phenyliminomethyl}benzoate](PBFEUB) were obtained by general synthetic methods. PBOEB and PBFOEB having the octenyloxy groups such as $-(CH_2)_6CH=CH_2$ showed ferroelectric switching, and their values of spontaneous polarization on reversal of an applied electric field were 120 nC/$cm^2$ and 225 nC/$cm^2$, respectively. PBEUB and PBFEUB having the undecyloxy groups such as $-{CH_2)_9CH=CH_2$ showed antiferroelectric switching, and their values of spontaneous polarization on reversal of an applied electric field were 120 nC/$cm^2$ and 140 nC/$cm^2$, respectively. We could obtain ferroelectric and antiferroelectric phases by controlling the number of carbon atom in alkenyloxy chains of bent-core molecules.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.135-136
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• 2006

Bismuth titanate ($Bi_4Ti_3O_{12}$, BIT) thin film has been studied intensively in the past decade due to its large remanent polarization, low crystallization temperature, and high Curie temperature. Substitution of various trivalent rare-earth cations (such as $La^{3+}$, $Nd^{3+}$, $Sm^{3+}$ and $Pr^{3+}$) in the BIT structure is known to improve its ferroelectric properties, such as remanent polarization and fatigue characteristics. Among them, neodymuim-substituted bismuth titanate, ((Bi, Nd)$_4Ti_3O_{12}$, BNT) has been receiving much attention due to its larger ferroelectricity. In this study, Ferroelectric $Bi_{3.3}Nd_{0.7}Ti_3O_{12}$ thin films were successfully fabricated by liquid delivery MOCVD process onto Pt(111)/Ti/$SiO_2$/Si(l00) substrates. Fabricated polycrystailine BNT thin films were found to be random orientations, which were confirmed by X-ray diffraction and scanning electron microscope analyses. The remanent polarization of these films increased with increase in annealing temperature. And the film also demonstrated fatigue-free behavior up to $10^{11}$ read/write switching cycles. These results indicate that the randomly oriented BNT thin film is a promising candidate among ferroelectric materials useful for lead-free nonvolatile ferroelectric random access memory applications.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.407-410
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• 2005

We report on a high speed flexible display based on a deformed helix ferroelectric liquid crystal (DHFLC) in a vertically aligned configuration. The mechanical stability of the flexible DHFLC display was achieved using a periodic array of columnar spacers formed directly on the top sides of in-plane electrodes by the photolithography technique. Several unique features of display performances such as flexibility, uniform alignment, fast response, and gray scale capability were obtained.