• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 학술대회 및 기술세미나 논문집 디스플레이 광소자
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• pp.64-65
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• 2006

We studied the nematic liquid crystal (NLC) alignment capability by the IB(on bean) alignment method on a NDLC(Nitrogen Diamond Like Carbon) as a-C:H thin film, and investigated electro-optical performances of the IB aligned IPS(In plane switching}cell with NDLC surface. A good LC alignment by IB exposure on a NDLC surface was achieved. Monodomain alignment of the IB aligned IPS cell can be observed. The goodelectro-optical (EO) characteristics of the IB aligned IPS cell was observed with oblique IB exposure on the NDLC as a-C:H thin film for 1 min.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1996년도 The 9th KACG Technical Annual Meeting and the 3rd Korea-Japan EMGS (Electronic Materials Growth Symposium)
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• pp.526-526
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• 1996

The single crystal of LiTaO3 is well known eletro-optic material as well as the piezoelectric one applied to SAW filter. LiTaO3 has large electro-optic effects, so applied to optical switch, acosto-optic deflector, and optical memory device using photorefractive effects. The crystal growth of SAW-grade LiTaO3 has been studied many aspects, but there is no detail research about optic-grade crystal growth. The conditions of optic-grade LiTaO3 single crystal are as below. The optical transmittance must be over 75%, and axial and radial concentratiom uniformity below 1%. The variation of Curie temperature depending on Li/Ta ratio must be also below 2$^{\circ}C$ and no internal no internal cracks and defects. Because of the limitation of crystal quality, the growing of optic-grade LiTaO3 single crystal is very difficult compared with the growing of SAW-grade. In this research, upper conditions of optic-grade single crystal was investigated after growing of 1 inch diameter and 1.5 inch length LiTaO3 single crystal having no internal cracks and defects using Czochralski method. Curie temperature was determined with DSC and measuring capacitance and lattice parameter was calculated about the grown crystal and ceramic powder samples of various Li/Ta ratio. The result of Tc variation was below 1.2$^{\circ}C$ all over the grown crystal, so it is confirmed that LiTaO3 was grown under congruent melting composition having optical homogeniety. Also, the optical transmittance was about 78%, which was sufficient for optical device.

• 한국광학회지
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• 제35권4호
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• pp.164-169
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• 2024

재귀적 수치 계산법을 적용하여 모바일 폰용 카메라 광학 모듈의 기초 설계를 진행하였다. 38도의 반각 필드에 대한 결상 성능을 높이기 위하여 6개의 비구면 렌즈로 광학계를 구성하였으며, 소형 기기인 모바일 폰에서의 적용성을 높이기 위하여 전체 길이는 5 mm로 제한하였다. 기초설계에서 얻은 데이터를 바탕으로 Zemax 설계 툴을 사용하여 최적화 설계를 진행하였으며, 최적화된 광학계의 결상 성능은 280 lines/mm 패턴에 대한 modulation transfer function (MTF) 값이 19% 이상이고 다파장 광선에 대한 상 왜곡도는 최대 1.0% 이내임을 확인할 수 있었다. 본 논문을 통하여 재귀적 수치 계산법을 사용한 소형 모바일 폰 카메라의 기초설계가 가능함을 검증할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1929-1931
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• 1996

In this work, it is proposed new PD(partial discharge) detection technique using electro-optic effect, for which partial discharges generated from needle-plane electrode in air were detected through optical measuring system by use of $LiNbO3_3$ electro-optic crystal. As a result, it is noticed that PD measurable phase intervals are limited by the asymmetrical D-E hysteresis loop of the crystal with defects and half-wave voltage. However, both number of measured PD pulses and their amplitude were increased with applied voltage, which likely implies that it is possible to detect PD through newly proposed electro-optic method.

• 마이크로전자및패키징학회지
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• 제22권1호
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• pp.1-5
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• 2015

Recently, data throughput of smart electric devices increases dramatically. There is a great interest in a new technology which exceeds the limit of electrical transmission method. Optical PCB can supplement the weakness of electrical signal processing, the research for optical PCB is very active. In this paper, we propose the thermal imprint lithography process to fabrication optical layer of optical PCB and experiment to optimize the process conditions. We confirm process time, pressure, process temperature, demolding temperature and fabricate optical interconnection structure which has $45^{\circ}$ tilted mirror surface for confirm the interconnection efficiency.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1992년도 춘계학술대회 논문집
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• pp.54-57
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• 1992

An electro-optical single modulator is fabricated in X-cut LiNbO$_3$by the annealed proton exchange and self-aligned method. First, the effect of annealing is characterized by examining single optical modulator. It is found that by controlling the annealing time, the single optical modulator can be made widely variable. The on-off state of modulator is performed by annealing process and self-aligned electrodes are used in fabricating the single modulator. The optical single modulator has very good figures of merits : the measured on-off switching voltage of about 2.7V.

• 한국광학회지
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• 제30권6호
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• pp.230-236
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• 2019

저렴한 retro-반사지와 미소 전자 기계 시스템(micro electro-mechanical system, MEMS) 거울을 이용한 실내용 무선 광 통신용 위치 탐색 및 자동 링크 정렬 방법을 제안하고 실험하였다. 직접적인 가시선(line of sight, LOS) 확보를 위하여 retro-반사지에서 돌아온 빛으로부터 수신단 위치를 파악하고 MEMS 거울을 통한 빔 조종으로 통신 링크를 자동 정렬하였다. 자동 정렬된 광 링크를 통하여 7 m 전송 거리에서 2.5 Gb/s NRZ 신호를 전송하여 비트 에러율 10^-12에서 수신 감도 -31.87 dBm의 성능을 가졌다.

• 한국의학물리학회지:의학물리
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• 제25권2호
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• pp.116-121
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• 2014

본 본문은 Bio-MEMS 공정으로 제작한 마이크로 세포 분석 바이오칩을 사용하여 적혈구의 광학적 특성을 전압으로 측정한 실험이다. Bio-MEMS 공정을 이용하여 세포의 원활한 이동과 측정 분석에 사용되는 글라스에 채널 패턴 에칭을 위하여 포토리소그래피(photolithography)와 산화완충식각(BOE: buffered oxide etchant) 공정 조건, 세포 분석과 정보 전달에 사용되는 광섬유의 에칭을 위하여 산화완충식각 공정 조건, 세포나 유체를 칩과 외부의 전달 등에 사용되는 글라스의 홀을 위하여 전기화학방전(ECD: electro chemical discharge) 공정 조건, 글라스 접합을 위한 자외선반응접합(UVSA: ultraviolet sensitive adhesives) 공정 조건을 정립하였다. 또한 유체나 세포의 흐름 제어를 위한 라미나 흐름 조건, 적혈구세포에 대한 산란빔 파형을 측정하였다. 적혈구 실험을 통하여 출력 광섬유의 각도에 따른 산란빔이 출력측의 광섬유각도가 $0^{\circ}$일 때 약 17 V, 각도가 $5^{\circ}$일 때 약 10 V, 각도가 $10^{\circ}$일 때 약 6 V, 각도가 $15^{\circ}$일 때 약 4 V의 전압(Vpp)으로 측정되었다. 따라서 마이크로 세포 분석 바이오칩 제작의 소형화, 단순화, 공정신간 단축, 정량화하였고 적혈구의 광학적 특성을 측정을 측정함으로써 의공학(biomedical), 바이오칩공학(biochip), 반도체공학(semiconductor), 생물정보학(bioinformatics) 등의 응용과학 분야 발전에 기여할 것으로 기대한다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1990년도 추계학술대회
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• pp.33-37
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• 1990

Endoscope system is the device that observe interior the body. It has some demerits because it use of optical fibers. The resolution of images depends on the number of optical fibers, it is impossible that several people observe at the same time and it needs special camera in order to record images. In order to overcome these demerits, electro endoscope system using CCD(Charge Coupled Device) has been developed recently. If the diameter of insertion tube is thinner, it is easier to be examined by thin endoscope system. At the present time, we develope these type of electro endoscope system in the department of SNU biomedical engineering. Moreover, we are researching an algorithm of the 3D-reconstruction of interior of the gaster. In this paper, a method for 3D information detection using electroendoscopic image sequence has been presented.

• 한국전기전자재료학회논문지
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• 제14권7호
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• pp.600-605
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• 2001

The electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photo-aligned with polarized UV exposure on various blending photopolymer surfaces were investigated. Excellent LC alignment and voltage-transmittance (V-T) characteristics for TN-LCD photo-aligned with polarized UV exposure of normal incidence on the blending photopolymer (polyimide (PI) +PM4Ch(poly(4-methacryloyloxy chalcone))) surface containing chalcone group can be achieved. The EO performances for the TN-LCD photo-aligned on the blending photopolymer can be improved due to the photosensitivity by long side chain of the photopolymer.