• Title/Summary/Keyword: Bistability

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Nonlinear guided-wave properties in planar waveguides with two nonlinear bounding thin films (비선형 박막으로 둘러싸인 평면 광도파로에서의 비선형 도파광 특성)

  • 정종술;송석호;이일항
    • Korean Journal of Optics and Photonics
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    • v.7 no.2
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    • pp.136-141
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    • 1996
  • We present a novel description of TE nonlinear guided waves in planar waveguides with two nonlinear bounding thin films. The nonlinear dispersion relations of the nonlinear waveguides are obtained by adopting the nonlinear transfer matrix. The optical properties obtained from these equations include: the power dependence of mode indices, the transition of the field maximum location, and the power distribution. The planar waveguide with self-focusing nonlinear layers shows the optical bistability of power-dependent mode indices, and the critical powers for the optical bistability increase with decreasing thickness of the nonlinear layers. The power distributions display the optical bistabilities, similar to those of nonlinear Fabry-Perot etalon.

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Liquid crystal alignment on the multiply photo-treated layers by the interfered laser light

  • Lee, Eun-Kyu;Kim, Jong-Hyun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.838-841
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    • 2006
  • Orientational alignment patterns proved that they are very useful for realizing diverse properties of liquid crystals. Here we tried to produce the patterns combining interfered laser light and double irradiations. A photo-isomerizable polymer doped with azo dye, which induce uniform liquid crystal alignment to the uniform laser irradiation, was used as the alignment layer. Double irradiations into two orthogonal directions brought the orientation patterns similar to the checkerboard. It indicates the possibility of bistability on those patterns.

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Characteristics of a Reflective Fabry-Perot Etalon with Kerr Medium (Kerr 매질로 채워진 반사형 Fabry-Perot etalon의 동작 특성)

  • 정종술;곽종훈;황월연;서호형;이일항
    • Korean Journal of Optics and Photonics
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    • v.5 no.1
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    • pp.31-36
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    • 1994
  • We present a structure of a reflective Fabry-Perot etalon with nonlinear Kerr material (Kerr FP etalon), and report the polarization conversion and the optical bistability of polarization conversion. A device proposed has high polarization conversion ratio, 100% or so, and good/broad optical bistablity for input pump intensity.

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Characterization of CW Ring Dye Laser (연속발진 고리형 색소레이저의 동작특성 연구)

  • 김재완
    • Proceedings of the Optical Society of Korea Conference
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    • 1991.06a
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    • pp.65-65
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    • 1991
  • 레이저 분광학의 연구에 있어서 고출력이며 좁은 선폭인 레이저광이 요구된다. 특히 고리형 공진기 레이저는 이득물질에서 공간 홀 버닝 효과 (Spatial Hole Burning effect)를 줄이거나 없앨수 있으므로 정상파로 발진하는 레이저에 비하여 높은 출력의 단일모드 발진을 얻을 수 있다. 8자형 고리 공진기 레이저에서 외부 되반사경과 코팅되지않은 에탈론의 조합을 사용하여 높은 출력의 단일모드를 얻었다. 색소분자의 에너지 준위를 2준위 구조로 가정하여 고리형 색소레이저에 있어서의 단일모드 발진의 안정성(Stability)을 살펴보았으며 양방향으로 단일모드 발진을 하는 경우에 있어서의 쌍안정(Bistability) 상태를 확인하였다.

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Development of Low Anchoring Strength Liquid Crystal Mixtures for Bistable Nematic Displays

  • Stoenescu, D.;Lamarque-Forget, S.;Joly, S.;Dubois, J.C.;Martinot-Lagarde, Ph.;Dozov, I.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.97-100
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    • 2005
  • The recent Bistable Nematic ($BiNem{(R)}$) LCD technology presents long term bistability, high level passive matrix multiplexing and high optical quality. The BiNem device, based on anchoring breaking, needs specific low anchoring strength materials - alignment layers and liquid crystal mixtures. We present here our approach to develop nematic mixtures with wide enough temperature range and low zenithal anchoring energy.

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Liquid Crystal Alignment on the Multiple Photo-treated Layers by the Interfered Laser Light

  • Lee, Eun-Kyu;Kim, Jong-Hyun
    • Journal of Information Display
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    • v.8 no.1
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    • pp.6-9
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    • 2007
  • Orientational alignment patterns have been proven to be that they are very useful for realizing diverse properties of liquid crystals. Here we produced the patterns combining interfered laser beams. A photo-isomerizable polymer including azo unit, which induces nematic liquid crystal alignment to the polarized laser light, was used as the alignment to layer. Double irradiations into two orthogonal directions brought the orientation patterns similar to the checkerboard. It indicates the possibility of bistability on those patterns.

Self-pulsing, Bistablilty, and Chaos in a Laser Diode with Delayed Optoelectronic Feedback (지연 광전궤환이 가해진 레이저 다이오드에서의 자기발진, 쌍안정성 및 혼돈)

  • 이창희
    • Proceedings of the Optical Society of Korea Conference
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    • 1989.02a
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    • pp.107-112
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    • 1989
  • We observe experimentally self-pulsing, subharmonic generation, spectral bistability, and chaos in a stable laser diode with delayed optoelectronic feed-back. The laser diode emits 200 ps optical pulses with 1.1 GHz repetition rate in the self-pulsing region. The bistable region critically depends on the closed loop gain of the system. We also explain observed experimental result.

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High Performance $2{\times}4$ S-SEED Array with Extremely Shallow Quantum Well and Asymmetric Fabry-Peort Cavity Structure (저장벽 양자우물고조와 비대칠 패브리-페로 공명기 구조에 의한 고성능 $2{\times}4$ S-SEED Array 구현)

  • 권오균;최영완;김광준;이일항;이상훈;원용협;유형모
    • Korean Journal of Optics and Photonics
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    • v.5 no.1
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    • pp.144-151
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    • 1994
  • We designed and fabricated a $2{\times}4$ symmetric self electro-optic effect device array using GaAs/ AIo.04 G$\DeltaR$), and optical bistability loop width ($\Delta$). The average values of the elements of the $2{\times}4$ S-SEED array were CR~13.1, R~24%, and $\Delta$~91%. It was found that the AFP cavity structure enhances the self-biased optical bistability in ESQW-SEED under no external bias. That is due to the decreased intrisic region thickness in AFP-SEED structures, and which increases the built-in electric fields. The zero-biased S-SEED showed CR of ~4.7, R~9%, and $\Delta$~22%.X>~22%.

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Development of Low Anchoring Strength Liquid Crystal Mixtures for Bistable Nematic Displays

  • Dozov, Ivan;Stoenescu, Daniel-Nicusor;Lamarque-Forget, Sandrine;Joly, Stephane;Dubois, Jean-Claude;Martinot-Lagarde, Philippe
    • Journal of Information Display
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    • v.6 no.3
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    • pp.1-5
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    • 2005
  • The recent Bistable Nematic ($BiNem^{(R)}$) LCD technology presents long term bistability, high level passive matrix multiplexing, gray levels capabilities and high optical quality. The $BiNem^{(R)}$ device, based on anchoring breaking, needs specific low anchoring strength materials - alignment layers and liquid crystal mixtures. We present here our approach to develop nematic mixtures with wide enough temperature range and low zenithal anchoring energy.