• 대한기계학회논문집
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• 제12권4호
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• pp.806-812
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• 1988

본 연구에서는 상술한 바와 같이 광간섭에 의한 포성재료 및 초저온, 초고온 에 사용되는 재료의 응력확대계수 측정법에 대한 응용의 한 방법으로서 테프론 균열 주형법에 의한 인공열을 에폭시(epoxy)판으로 주형하고 레이저 간섭법에 의한 응력 확대계수의 측정을 시도하여 광소자(phototransistor)로 추적하기에 적당하고 선명한 간섭무늬를 얻을 수 있는 판사면 중심간의 구이를 실험적으로 결정하고 광탄성법에 의 한 실험결과와 비교하여 레이저 간섭법의 실용성을 확인하려고 한다.

• 한국전기전자재료학회논문지
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• 제20권3호
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• pp.268-272
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• 2007

A fully integrable InP/InGaAs HPT with an ITO emitter contact was first fabricated by employing a $SiO_2$ passivation layer. The electrical and the optical characteristics of the HPT with a passivation layer were measured and compared with those of the HPT without a passivation layer. The only noticeable difference was the increased emitter series resistance of the HPT with a passivation layer. AES analysis was performed to explain the reason of the increased emitter series resistance. Results show that PECVD $SiO_2$ deposition and annealing processes cause the diffusion of oxygen to the interface and the depletion of tin at the interface, which may be responsible for the increase of the series resistance.

• 대한화학회지
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• 제18권1호
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• pp.47-49
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• 1974

감광트랜지스터 끝에 렌즈를 부착시켜 지향성을 충분히 좋게 한 것을 유리관 끝에 접착 밀봉하여 광도 검지기를 만들었다. 적정용액속에 이 감지기를 수직으로 담거 세우고, 밑에서 빛을 쪼여 올리면서 적정하는 방법을 발전시켜, 밝은 실험실에서 흡광광도 적정을 실시할 수 있게 하였다.

• 한국광학회지
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• 제2권4호
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• pp.233-241
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• 1991

Structures, fabrication, and characteristics of top-surface-emitting GaAs four quantum well microlaser are described. The microlasers have good room-temperautre CW characteristivs. The maximum CW laser output is >3mW from a 30 $\mu\textrm{m}$ diameter microlaser and the maximum differential quantum efficiency is >70% from a 10 $\mu\textrm{m}$ diameter microlaser. Active surface emitting laser logic devices are designed and fabricated as a discrete version of a top-surface-emitting laser and heterojunction phototransistor. The active surface emitting laser logic device have high optical gain (>20 overall, >200 differential) and very high on/off ratio. Two-dimensional arrays of top-surface-emitting microlasers and active surface emitting laser logic devices will be critical elements for optical computing, photonic switching and neural network applications.

• 센서학회지
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• 제3권2호
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• pp.50-56
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• 1994

살충제와 농약의 성분인 유기인 화합물 측정을 위한 광섬유 바이오센서가 개발되었다. 개발된 광섬유 바이오센서에서는 유기인 화합물에 의해 직접적으로 저해되는 AChE효소 (acetylcholinesterase)의 반응이 용액 pH의 변화를 일으킨다는 원리를 이용하여 그 변화를 광을 이용하여 측정함으로써 유기인 화합물을 측정하였다. pH 변화 정도를 광을 이용하여 측정하기 위해서 사용되어진 효소의 반응과 광원에 알맞은 산-염기 지시약인 리트머스를 선택하였다. 장시간 사용 시에도 활성을 유지시키고 재사용을 가능하게 하기 위하여 AChE효소는 Ca-alginate gel에 포괄시켜 센서의 반응기 내벽에 고정화시켰다. 장치를 소형화하고 원격 측정이 가능하게 하기 위하여 광섬유를 사용하여 빛을 전송하였다. 광원으로써는 생성물의 영향을 받지 않는 632 nm의 파장을 갖는 He-Ne laser를 사용하였고, 광섬유는 가격이 저렴한 플라스틱 광섬유를 사용하였고, 광 수신 장치로는 phototransistor를 사용하였다. 본 연구에서 제안된 광섬유 바이오센서는 유기인 화합물의 농도에 대하여 0 ppm 에서 1.5 ppm까지 선형적인 신호를 가지고 있으며 측정 시간은 5분이었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2441-2444
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• 2003

This paper describes fabrication of a micro cell counter integrated with an oxygen micropump and Sephadex G-25 beads counting experiment. The device utilized a phototransistor, microwindow, and light source of microscope for beads detection. Microheater and microchannel were used for pumping and guiding of beads to the microwindow. Counting capability of the device was tested with a peristaltic pump and the measured signals (${\sim}10\;mV$) with oscilloscope showed peak shape when beads passed the microwindow. Pumping of beads by the oxygen micropump was carried out by heating paraffin, which enveloped manganese dioxide (catalyst), to trigger the decomposition of hydrogen peroxide into water and oxygen. It lasted for 5 min with $7\;{\mu}l$ of wt. 30 % hydrogen peroxide. Beads counting by oxygen micropump showed peaks ($2{\sim}20\;mV$) with $30\;{\mu}l$ of beads sample and the number of peaks by magnitude was acquired.

• 산업기술연구
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• 제37권1호
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• pp.27-31
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• 2017

In this paper, we have extended the research on the infrared sensor which has been limited to the plane. The reflection mechanism of the light on the curved surface is analyzed according to the curvature change and the emitted angle of photodiode and verified through experiments. The difference in the curvature causes a difference in the measurement distance, and also changes the intensity of the light coming into the phototransistor, thereby causing a difference in the output voltage. However, the difference in the output voltage due to the curvature change can be solved by adjusting the emitted angle of the photodiode to minimize the spot area formed on the curved surface regardless of the curvature. Therefore, it is possible to measure the distance by using the infrared sensor regardless of the curvature by aligning the photodiode to the center of the curved surface and adjusting the angle of the photodiode.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.125-126
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• 1998

Pulse conduction velocity is determined by areterial compliance, which is changed by lateral pressure of arterial wall. Hydrostatic pressure of the limb vessel is changed by body position, especially in elevated arm. The arterial pulse in the finger causes the blood volume to change, changing the optical density of the blood. Photoplethysmograph of index finger was obtained by LED and phototransistor. Pulse transmission time(PTT) was measured by the interval between the peak of ECG R wave and the peak of the finger plethysmogram. PTT was increased by upward position of arm, and decreased by downward position of the arm compared to horizontal position. This result suggests that relationship between finger plethysmography and postural change could be applied to evaluate clinical cardiovascular status.

• 한국전기전자재료학회논문지
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• 제15권5호
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• pp.449-454
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• 2002

The use of a thin film of indium between the ITO and the $n^+-lnP$ contact layers for InP/InGaAs HPTs was studied without degrading its excellent optical transmittance properties. $ITO/n^+-lnP$ ohmic contact was successfully achieved by the deposition of indium and annealing. The specific contact resistance of about $6.6{\times}10^{-4}\Omega\textrm{cm}^2$ was measured by use of the transmission line method (TLM). However, as the thermal annealing was just performed to $ITO/n^+-lnP$ contact without the deposition of indium between ITO and $n^+-lnP$, it exhibited Schottky characteristics. In the applications, the DC characteristics of InP/InGaAs HPTs with ITO emitter contacts was compared with those of InP/InGaAs HBTs with the opaque emitter contacts.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1351-1355
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• 2018

The photocurrent characteristics of zinc-oxide (ZnO) thin-film transistors (TFTs) prepared using radio-frequency sputtering and spin-coating methods were investigated. Various characterization methods were used to compare the physical and the chemical properties of the sputtered and the spin-coated ZnO films. X-ray photoelectron spectroscopy was used to investigate the chemical composition and state of the ZnO films. The transmittance and the optical band gap were measured by using UV-vis spectrometry. The crystal structures of the prepared ZnO films were examined by using an X-ray diffractometer, and the surfaces of the films were investigated by using scanning electron microscopy. ZnO TFTs were prepared using both sputter and solution processes, both of which showed photocurrent characteristics when illuminated by light. The sputtered ZnO TFTs had a photoresponsivity of 3.08 mA/W under illumination with 405-nm light while the solution-processed ZnO TFTs had a photoresponsivity of 5.56 mA/W. This study provides useful information for the development of optoelectronics based on ZnO.