• Title/Summary/Keyword: Optical bistability

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Optical transmission characteristics of a bistable TN LCD (쌍안정 TN LCD의 광투과 특성)

  • 최길재;김양수;강기형;정태혁;윤태훈;김재창;남기곤;이응상
    • Korean Journal of Optics and Photonics
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    • v.8 no.3
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    • pp.218-222
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    • 1997
  • We fabricated a bistable TN LCD with 180$^{\circ}$ twist angle and confirmed that it has a fast switching response time and a high contrast ratio. We also investigated the effects of the amplitude and width of the reset and selection pulses on a bistable TN LC cell and the conditions of the bistability and the memory time. The range of d/p values showing the bistability is determinded for the pretilt angle according to the rubbing depth.

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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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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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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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All-optical Logic gate using the SOA/DFB-SOA with Broadband-Gain (광대역 이득을 가진 SOA/DFB-SOA를 이용한 전광 논리구현)

  • Kim, Young-Il;Kim, Jae-Hun;Lee, Seok;Woo, Heok-Ha;Yoon, Tae-Hoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.04b
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    • pp.109-111
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    • 2002
  • We have demonstrated all-opticalflip-flop based on optical bistability in a SOA/DFB-SOA with broadband gain. Input signal with the wavelength of 1340.23 nm or 1680.93 nm and the current of about 98% of the lasing threshold is injected into theDFB-SOA. Current injected into SOA is 80 mA All-optical flip-flop has various applications such as all-optical memory, demultiplexing, packet-header buffering, and retiming.

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Optical Bistability in Nonlinear Etalons Filled with NOA81 Optical Adhesive (NOA81 Optical Adhesive를 중간층으로 하는 비선형 Etalon에서 나타나는 광쌍안정현상에 대한 연구)

  • Kong, Hong-Jin;Hwang, Wol-Yon;Lee, Sang-Soo
    • Proceedings of the KIEE Conference
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    • 1987.11a
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    • pp.387-391
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    • 1987
  • We have observed the optical bistabilities at $5145{\AA}$ in nonlinear etalons filled with NOA8l optical adhesive which is cured with UV light under the temperature gradient of $7^{\circ}C/mm$ on the NOA81 layer surface. The critical switch-on irradiance and switch-on time are $17\;KW/cm^2$ and $350{\mu}sec$. respectively. The switching contrast of up to 8 observed in NOA81 etalons is higher than that of ZnS or ZnSe interference filter, and the thermo-optic coefficient (dn/ndT) of NOA81 is measured to be at least $-3.8{\times}10^{-4}/^{\circ}C$ which is larger in magnitude than that of ZnS or ZnSe.

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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

  • 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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