• Title/Summary/Keyword: Electro-optical (EO)

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Establishment of Test & Evaluation Criteria in the Military Electro-Optical / Infrared Devices (군용 EO/IR장비의 시험평가 기준 정립방안)

  • Park, Jong Wan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.5
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    • pp.613-617
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    • 2016
  • Development-concerned parties, business managers and test evaluators have experienced conflicts among themselves due to the absence of standardized criteria for military electro-optical(EO) and infrared(IR) devices in test evaluation planning and evaluation phases. Therefore, establishment of objectified test and evaluation criteria for EO/IR devices is required. This paper applies South Korea's weather measurement average of minimum 15 km for visibility range, 3 bar from Johnson criteria for EO device and 4 bar from NATO's STANAG-4347 for IR device for target type, and 50 % probability for evaluation criteria, respectively. Based upon these criteria, this paper will establish suitable criteria that are improved for development weapon system in consideration of required capability of demanding forces and field environment.

Optical Interferometric Characterization of Nonlinear Optical Polymer Thin Films

  • Wu, J.W.
    • Journal of the Korean Vacuum Society
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    • v.7 no.s1
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    • pp.149-155
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    • 1998
  • The linear electro-optic (EO) effect is one of the second-order nonlinear optical effects existing in a noncentrosymmetric macroscopic system. In a polymer thin film, the noncentrosymmetry is achieved by electric field poling. The magnitude of the linear EO response is determined through the orientational distribution function of hyperpolarizable molecular dipoles. The relation between the linear EO coefficient and the second-order nonlinear optical susceptibility is explained. Three different methods of measuring the linear EO coefficient of a poled nonliner optical polymer thin film are introduced and discussed. All of them make use of the interferometric technique, the difference being in the optical parameters which are interfering.

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A Study of Laboratory Measurement of EO GRD Resolution for Airborne EO/IR Sensor (항공용 EO/IR 센서의 EO GRD 분해능 실험실 측정 연구)

  • Huh, Joon;Kim, Chang-Woo;Kim, Sungsoo;Kim, Byoung-Wan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.6
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    • pp.793-799
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    • 2014
  • EO GRD(Ground Resolved Distance) resolution of airborne EO/IR(Electro-Optical/Infrared) sensor is a critical factor in test and evaluation for EO sensor performance. We propose the laboratory measurement set-up for EO GRD by constructing optical collimator which includes integrated sphere, blackbody, equivalent 3-bar target and 6 DOF motion simulator. GRD is measured in the photographic imagery of bar targets by 3 different distances for 3 EO/IR sensors and the measured results were analyzed statistically. We found that at least 7 sheets of imagery are needed in order to obtain meaningful EO GRD. The result of statistical analysis shows that the distribution of the measured GRD is nearly symmetric about the average GRD, and the better imagery ratio above the average GRD is about 40~70%. Also from the best GRD analysis, it is estimated that the design goal for EO GRD should be 30% superior to the required GRD.

Electro-Optical Characteristics of Plastic STN Cell on the Polyimide Surface (폴리이미드 표면을 이용한 플라스틱 STN 셀의 전기 광학 특성)

  • Kim, Jong-Hwan;Kim, Kang-Woo;Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.1086-1089
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    • 2003
  • We investigated the electro-optical (EO) performances of the super twisted nematic liquid crystal display (STN-LCD) on the polyimide (PI) surface using polymer film. Monodomain alignment of the plastic STN-LCD can be observed. A stable voltage-transmittance (V-T) curve of the plastic STN-LCD was observed on the polyimide (PI) surfaces using polymer film. Also, a faster response time for the plastic STN-LCD on the polyimide (PI) surfaces using polymer film can be achieved. Therefore, the EO performances of the plastic STN-LCD on the polyimide (PI) surfaces using polymer film is almost the same as that of the glass STN-LCD on a polyimide (PI) surface.

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Chemical Structural Effects of Polyimides on the Alignment and Electro-optical Properties of Liquid Crystal Cells

  • Paek, Sang-Hyon;Wonseok Dong
    • Macromolecular Research
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    • v.12 no.3
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    • pp.251-257
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    • 2004
  • The nature of the nematic liquid crystal (LC) alignment induced by the rubbed polyimide (PI) alignment layers (ALs) and the electro-optical (EO) properties of the LC cells are expected to depend on the chemical and physical features of the PI. By employing five pyromellitic dianhydride (PMDA)-type PIs having different functionalities, we have studied the effects of the PI's structure and chemistry on the alignment characteristics and the cell's EO properties. Increasing the flexibility of the PI increases the pretilt angle and tends to improve the alignment stability. On the other hand, the rigid, fluorinated PI displays poor stability for LCs and induces a less stable/uniform LC alignment and, subsequently, a small pre tilt angle. It also transpired that fluorination of the PI deteriorated the voltage-transmittance characteristics and the voltage holding ratio; increasing the flexibility of the PI structure improves these EO properties. The finding that the qualitative trends for the PI's functionalities are similar for both the alignment and EO properties suggests that the EO properties are closely related to the alignment characteristics, which are determined by short-range interactions between LC and PI molecules.

Macroscopic Nonlinear Optical Properties of Tricyanopyrrolidene Chromophore Containing Amorphous Polycarbonate: Effect of Molecular Lateral Moiety in the Conjugative Structure

  • Cho, Min-Ju;Lee, Sang-Kyu;Jin, Jung-Il;Choi, Dong-Hoon
    • Macromolecular Research
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    • v.14 no.6
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    • pp.603-609
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    • 2006
  • Tricyanopyrrolidene chromophores were prepared in order to compare their macroscopic nonlinear optical (NLO) properties with a conjugated structure through the long molecular axis. A thiophene or phenyl ring was tethered to an ethylenic bond; it may act as a lateral moiety to disrupt the planarity of a chromophore and lessen the electrostatic interaction. Thin film composites of these chromophores dissolved in amorphous polycarbonate (APC) were fabricated. Real time pole and probe method was employed to investigate the change of electro-optic (EO) signal during poling. The EO properties and their relaxation behaviors of the guest-host systems containing newly synthesized chromophores were investigated in detail.

LOS Moving Algorithm Design of Electro-Optical Targeting Pod for Joystick Command (조이스틱 명령에 따른 Electro-Optical Targeting Pod의 LOS 이동 알고리즘 설계)

  • Seo, Hyoungkyu;Park, Jaeyoung;Ahn, Jung-Hun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.10
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    • pp.1395-1400
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    • 2018
  • EO TGP(Electro-Optical Targeting Pod) is an optical tracking system which has various functions such as target tracking and image stabilization and LOS(Line of Sight) change. Especially, it is very important to move the LOS into a interest point for joystick command. When pilot move joystick in order to observe different scene, EO TGP gimbals should be operated properly. Generally, most EOTS just operate corresponding gimbal for joystick command. For example, if pilot input horizontal command in order to observe right hand screen, it just drive azimuth gimbal at any position. But in the screen, the image dosen't move in a horizontal direction because gimbal structure is Euler angle. And image rotation is occurred by elevation gimbal angle. So we need to move Pitch gimbal. So in the paper, we designed LOS moving algorithm which convert LOS command to gimbal velocity command to move LOS properly. We modeled a differential kinematic equation and then change the joystick command into velocity command of gimbals. This algorithm generate velocity command of each gimbal for same horizontal direction command. Finally, we verified performance through MATLAB/Simulink.

Fabrication of a Y-branch Phase Modulator Using an Electro-Optic Polymer (전기광학 폴리머를 이용한 Y 분기형 위상 변조기의 제작)

  • 오영훈;신상영
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.08a
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    • pp.34-35
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    • 2000
  • A Y-branch phase modulator made of an electro-optic(EO) polymer has been designed and fabricated. An EO polymer, PMMA-DR1, is used for the core layer, and UV-curable polymers, UV-15 and UV-15 LV, for the cladding layers. The rib type polymeric waveguides are fabricated by the reactive ion etching method and their EO effects are obtained by the poling process. The optical properties of the fabricated phase modulator are as follows: the halfwave voltage, $V_{\pi}$, is 25 V, the insertion loss of TM mode is 13.8 dB, and the intensity modulation is 0.17 % (V).

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Electro-Optical Characteristics of Plastic STN Cell using photoalignment method (광배향을 이용한 플렉시블 STN 셀의 전기 광학 특성)

  • Bae, Yu-Han;Hwang, Jeoung-Yeon;Kim, Jong-Hwan;Nam, Ki-Hyung;Lee, Whee-Won;Kim, Kang-Woo;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.1007-1009
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    • 2004
  • We investigated the electro-optical(EO) performances of the super twisted nematic liquid crystal display(STN-LCD) on the polyimide(PI) surface with polymer film using rubbing and photoalignment method. Monodomain alignment of the plastic STN-LCD can be observed. A faster response time for the photoaligned plastic STN-LCD on the polyimide(PI) surfaces can be achieved than rubbingaligned plastic STN-LCD.

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Electro-Optical Characteristics of Plastic STN Cell using Low Temperature Process (저온 공정을 이용한 플라스틱 STN 셀의 전기 광학 특성)

  • Kim, Kang-Woo;Hwang, Jeoung-Yeon;Kim, Jong-Hwan;Seo, Dae-Shik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.05a
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    • pp.202-205
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    • 2004
  • We investigated the electro-optical(EO) performances of the super twisted nematic liquid crystal display(STN-LCD) on the polyimide(PI) surface using polymer film. The NLC pretilt angles generated are about $18^{\circ}$ by the rubbing alignment method on thin plastic substrates. However, the pretilt angle are at about $13^{\circ}$ lower on the glass substrate than on thin plastic substrate. Monodomain alignment of the plastic STN-LCD can be observed. A stable voltage-transmittance(V-T) curve of the plastic STN-LCD was observed on the polyimide(PI) surfaces using polymer film. Also, a faster response time for the plastic STN-LCD on the polyimide(PI) surfaces using polymer film can be achieved.

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