• Title/Summary/Keyword: Electro-optical devices

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Electro-active Polymer and Dielectric Elastomer Technology for Haptic Interface, Muscular Enhancement, and Tunable Optical Components (전기가변 고분자 소재를 이용한 응용소자)

  • Yoon, J.W.;Park, S.K.;Mun, S.
    • Electronics and Telecommunications Trends
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    • v.34 no.4
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    • pp.108-116
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    • 2019
  • Electro-active polymers and dielectric elastomers have many intriguing properties that enable smart interfaces and electrically tunable optical systems, such as haptic feedback devices, artificial muscles, and expansion-tunable optical elements. These device classes are of great interest owing to their promising roles in next-generation technologies including virtual or augmented reality, human sensing and muscular enhancement, and artificial skins. In this report, we review basic principles, current state-of-the-art techniques, and future prospects of electro-active and dielectric elastomer technology. We describe chemical and physical properties of the most promising polymer substances, essential elementary architectures for artificial muscle-like functionalities, and their applications to haptic interfaces, muscular enhancement, and focus-tunable optical elements.

Noble LCD with a Single Supporting Substrate

  • Wook, Jung-Jong;Kim, Jae-Hoon
    • Journal of Information Display
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    • v.3 no.4
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    • pp.4-7
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    • 2002
  • A recently developed phase separated composite film method has been employed to fabricate a liquid crystal (LC) based electro-optical device using a single glass substrate. The resulting device is made of adjacent parallel layers of LC and polymer maded by phase separation. The LC layer is confined between the solidified polymer layer on one side and the glass substrate on the other. The electro-optical properties of these devices demonstrate their technological potential in light weight and hand-held electronic products.

Electro-optical characteristics of liquid crystal alignment layer modified by ion beam irradiation (액정배향막 표면 개질에 따른 전기광학적 특성연구)

  • Oh, Byeong-Yun;Seo, Dae-Shik
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.513-514
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    • 2008
  • The potential of non-rubbing technology for applying to display devices was demonstrated by irradiating a high density argon ion beam (IB) on a polyimide (PI) as a liquid crystal alignment layer. The superior electro-optical characteristics were obtained, compared to rubbed PI, Although the low pretilt angle was created on the IB irradiated PI.

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Optical Bistability and Multistability Using Electro-Optic Feedback (전기 광학적 궤환을 이용한 광 쌍안정성과 다 안정성)

  • Lee, Chang-Hee;Cho, Kun-Ho;Shin, Sang-Yung;Lee, Soo-Young
    • Proceedings of the KIEE Conference
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    • 1987.07a
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    • pp.64-67
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    • 1987
  • We demonstrate the optical bistability and multistability using light emitting devices, a photodetector, and transistors under the positive electro optic feedback. Its operating principle and high speed operation Scheme are also described.

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Electro-optical Characterization of OLED Device

  • Lee Soon-Seok;Kim Ki-Seok;Lim Sung-Kyoo
    • International Journal of Contents
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    • v.2 no.3
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    • pp.6-10
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    • 2006
  • Small molecule OLED devices were fabricated and the electro-optical characteristics were analyzed. The luminance and color coordinate of the fabricated OLED device were $24,390cd/m^2$ and (x=0.15, y=0.22), respectively. Current efficiency of 6.8 cd/A and power efficiency of 2.4 lm/W were also obtained under DC operating condition. Transient light intensity was also measured by using Si photodiode.

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Highly Efficient Red Phosphorescent OLEDs Employing a Multifunctional Oligofluorene Host

  • Tsai, Ming-Han;Su, Hai-Ching;Wu, Chung-Chih;Wong, Ken-Tsung;Li, Wen-Ren
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.663-666
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    • 2007
  • High-efficiency red phosphorescent OLEDs employing a novel red emitter and a multifunctional oligofluorene host are reported. With qazIr(acac) as the red phosphorescent dopant, a maximum external quantum efficiency of 19% and maximum power efficiency of 11 lm/W are achieved. In addition, single layer devices using such host and dopant materials have efficiencies up to 13%.

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Compact and Temperature Independent Electro-optic Switch Based on Slotted Silicon Photonic Crystal Directional Coupler

  • Aghababaeian, Hassan;Vadjed-Samiei, Mohammad-Hashem
    • Journal of the Optical Society of Korea
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    • v.16 no.3
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    • pp.282-287
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    • 2012
  • In this paper, we have proposed a principle to design a compact and temperature independent electro-optic switch based on a slotted photonic crystal directional coupler (SPCDC). Infiltration of the slotted silicon photonic crystal with polymer enhances the slow light and decreases the switching length, whereas the different signs of thermo-optic coefficients of the polymer and silicon make the proposed switch stable within $25^{\circ}C$ to $85^{\circ}C$ temperature range. The SPCDC structure is modified to increase poling efficiency of the polymer in the slot and to flatten the dispersion diagram of the even mode to minimize the switching length.

Simple polarimetric method for electro-optic coefficients

  • Kim, S.Y.;Lee, M.W.;Won, Y.H.;Kim, Y.K.;Lee, H.G.
    • Journal of the Optical Society of Korea
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    • v.3 no.1
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    • pp.23-26
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    • 1999
  • A simple technique to measure electro-optic coefficients has been developed. It is based on rotating analyzer polarimetry. With a coaxial configuration of the optically active polarizing devices, the synchronously digitized signals are Fourier analyzed to quantitatively determine the elliptical polarization of light and, hence, the electric field induced birefringence. This technique has the advantage that it does not require waveguiding, and since it is improved from the crossed polarizer method it measures the phase retardation directly. It has been applied for the precise determination of electro-optic coefficients of uniaxial LiNbO3 single crystals. The excellent agreeement with reported values confirms its usefulness toward accurate characterization of electro-optic coefficients of unknown specimens.

Electro-Optical Hysteresis by the In-plane Modulation of the Molecular Reorientation in Highly Twisted Nematic Liquid Crystal Devices

  • Yu, Chang-Jae;Jeong, Cherl-Hyun;Hong, Sun-Kwang;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1147-1150
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    • 2004
  • We studied on an electro-optical (EO) hysteresis, coming from the in-plane modulation of the molecular reorientation, in highly twisted nematic liquid crystal devices. Varying a ratio d/$P_0$ of the cell thickness d to the natural pitch $P_0$, the EO hysteresis and the twisted angle transition were observed and analyzed in terms of the periodicity of the in-plane modulation within the continuum theory.

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Effect of the Surface Dielectric Layer on the Electro-Optical Performances of Liquid Crystal Devices

  • Park, Jae-Hong;Jung, Min-Sik;Lee, Sin-Doo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.543-546
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    • 2003
  • We studied the dielectric layer effect on the electro-optical (EO) properties of liquid crystal (LC) devices together with numerical simulations. Recently, it has been reported that the surface dielectric layer affects significantly the EO performances of LC microlens arrays and wide-viewing LC displays. it is found that the operation voltage of the LC device decreases with increasing the dielectric constant or with decreasing the thickness of the dielectric polymer layer. The experimental data agree well with theoretical results predicted in a simple dielectric model within the continuum formalism.

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