• 센서학회지
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• 제13권5호
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• pp.350-355
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• 2004

A novel UV sensor was manufactured and characterized using the evanescentfield coupling between fiber-planar waveguide (PWG) coupler and prism. A spiroxazine dye was chosen as planar waveguide because its photochromic isomerization induced by UV irradiation. A novel UV sensor was proposed to measure the variation of refractive index and absorption coefficient simultaneously. The wavelength responses of these sensors by UV exposure times were measured 0.48 nm/sec, 0.757 nm/sec, and ATR output power variations were measured $-0.424{\mu}W$/sec and $-0.62{\mu}W$/sec when UV exposure power were 3 mW and 5 mW, respectively.

• 센서학회지
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• 제15권4호
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• pp.231-236
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• 2006

Single-mode planar waveguide type UV sensor was fabricated using SU-8 and photochromic dye. Polymer waveguide was fabricated $10{\mu}m$ width and $2{\mu}m$ thickness for single-mode operation. The UV sensor had an absorbance with $0.0396{\sim}0.114$ absorbance/mW respectively when the 5 mm sensing area was irradiated with UV for 3 sec. And sensor had a linear properties by sensing area variation. Proposed single-mode sensor had more excellent properties of UV sensitivity than other UV sensors.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.100-103
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• 2007

A microlens array has been required to improve light conversion efficiency in image sensors. A microlens array can be usually fabricated by photoresist reflow, hot-embossing, micro injection molding, and UV-imprinting. Among these processes, a UV-imprinting, which is operated at room temperature with relatively low applied pressure, can be a desirable process to integrate microlens array on image sensors, because this process provides the components with low thermal expansion, enhanced stability, and low birefringence, furthermore, it is more suitable for mass production of high quality microlens array. In this study, to analyze the optical properties of the wafer scale microlens array integrated image sensor, another wafer scale simulated image sensor chip array was designed and fabricated. An aspherical square microlens was designed and integrated on a simulated image sensor chip array using a UV-imprinting process. Finally, the optical performances were measured and analyzed.

• 한국광학회지
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• 제26권2호
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• pp.83-87
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• 2015

본 논문은 자외선 광학센서 개발에 관한 것이다. 기존에 반도체 기반 자외선 센서를 대체하기 위해 개발된 단주기 광섬유격자기반 자외선 센서에 대한 측정 민감도를 향상시키기 위한 다양한 장치들을 설계하고 실험을 통해 성능을 확인하였다. 최근 연구를 통해 자외선 흡수에 따라 인장력이 유도되는 아조벤젠 폴리머 재료와 장력에 따른 광섬유격자 특성 변화를 조합하여 새로운 자외선 센서의 개념이 제시되었다. 본 연구에서는 광섬유격자 기반 자외선 센서에서 흡수하지 못하고 통과되는 자외선 잔광을 반사판을 이용해서 다시 반사시켜 센서에서 재흡수되는 원리로 센서의 민감도를 향상시켰다. 본 논문에서는 반사판의 종류를 선정하고 반사판의 곡률반경을 최적화하였다. 또한 기존의 원통형 집광렌즈를 이용한 민감도 향상 기술을 접목 시켜 아무런 장치가 없을 때와 비교해서 약 15배의 성능을 향상시키는 결과를 얻었다. 또한 외부 환경 효과를 줄이기 위한 패키지 모듈을 제작하여 적용하고 그 특성을 분석하였다.

• Nuclear Engineering and Technology
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• 제50권5호
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• pp.751-757
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• 2018

In this article, a UV sensor that is an appropriate tool for fire detection has been designed and constructed. The structure of this UV sensor is an air-filled single-wire detector that is able to operate under normal air condition. A reflective CsI photocathode is installed at the end of the sensor chamber to generate photoelectrons in the ion chamber. An electric current is produced by accelerating photoelectrons to the anode in the electric field. The detector is able to measure the intensity of the incident UV rays whenever the current is sufficiently high. Therefore, the sensitivity coefficient of this sensor is found to be $7.67{\times}10^{-6}V/photons/sec$.

• 센서학회지
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• 제17권5호
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• pp.346-349
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• 2008

A metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) is proposed as an effective UV sensing device for integration with a GaN n-channel MISFET on auto-doped p-type GaN grown on a silicon substrate. Due to the high hole barrier of the metal-p-GaN contact, the dark current density of the fabricated MSM PD was less than $3\;nA/cm^2$ at a bias of up to 5 V. Meanwhile, the UV/visible rejection ratio was 400 and the cutoff wavelength of the spectral responsivity was 365 nm. However, the UV/visible ratio was limited by the sub-bandgap response, which was attributed to defectrelated deep traps in the p-GaN layer of the MSM PD. In conclusion, an MSM PD has a high process compatibility with the n-channel GaN Schottky barrier MISFET fabrication process and epitaxy on a silicon substrate.

• 마이크로전자및패키징학회지
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• 제25권3호
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• pp.37-41
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• 2018

본 논문에서는 UV 임프린트 기반의 평면 광 회로층을 이용한 산소농도 검출용 집적형 형광 프로브 모듈을 제안하였다. 제안된 형광 프로부 모듈은 광원과 형광 신호를 고효율로 전송할 수 있게 동일 광 경로를 가지는 비대칭 $1{\times}2$ 빔 분배기 형태로 설계되었으며, 이를 UV 임프린트 공정을 통해 제작하였다. 제작된 광 회로층의 끝단에 최적의 형광 염료 농도로 센서막을 코팅하여 산소 농도 검출용 광학 프로브 모듈을 구현하였다. 제작된 형광 프로부 모듈을 이용한 산소 농도 측정용 센서 시스템은 0%에서 20%의 가스 농도 범위에서 약 0.3%의 분해능까지 산소 농도를 검출 할 수 있었다. 이러한, 평면 광회로 기반의 형광 프로브 모듈은 저가의 집적형 산소 센서 검출 시스템을 가능하게 하여, 화학분야, 바이오 분야, 그리고 대기 및 수질 환경을 모니터링 하는 분야에 적용될 수 있을 것으로 기대된다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권9호
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• pp.444-449
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• 2001

In this paper, a novel ultraviolet sensor is presented based on a photoluminescent porous silicon. Porous silicon layer was formed by chemical etching of surface of pn junction in a $HF(48%)-HNO_3(60%)-H_20$ solution. Incident ultraviolet(UV) light is converted to visible light by photoluminescent porous silicon layer, and then this visible light generates electron-hole pairs in the pn junction, which produces a photocurrent flow through the device. In order to maximize detection efficiency, the peak sensitivity wavelength of the pn junction diode was matched with the peak wavelength of Photoluminescence from porous silicon layer. The porous silicon ultraviolet sensor showed a large output current as UV intensity increases and but very low sensitivity to visible light. The detection sensitivity of porous silicon sensor was calculated as 2.91mA/mW. These results are expected to open up a possibility that the present porous silicon sensor can be used for detecting UV light in a visible background, compared to silicon UV detectors which have an undesirable response to visible light.

• Korean Chemical Engineering Research
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• 제50권1호
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• pp.72-75
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• 2012

Strain-free AlGaN/GaN 나노선을 기판에 분산시킨 후 E-beam lithography(EBL)를 이용해 단일 나노선 자외선 센서를 제작하였다. 나노선의 구조적, 광학적 특성을 분석하기 위해 focused ion beam(FIB), photoluminescence, micro-Raman spectroscopy를 이용하여 나노선의 strain 및 형태를 조사하였다. 자외선 센서로서의 특성 여부를 확인하기 위하여 빛을 차단 한 조건과 자외선을 조사하는 조건하에서 current-voltage(I-V) 특성을 측정하였으며 각각 9.0 ${\mu}S$과 9.5 ${\mu}S$의 전기전도도(conductance)를 얻었다. 자외선 조사 조건하에서 excess carrier의 증가로 인해 전기전도도가 약 5%가 향상되었음을 알 수 있었다. 자외선을 반복적으로 조사하는 과정의 실험을 통해 우수한 포화 시간(saturation time)과 감쇠 시간(decay time)을 얻었다. 따라서 AlGaN/GaN 나노선은 자외선 센서로서 많은 가능성을 가지고 있음을 확인하였다.

• 한국광학회:학술대회논문집
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• 한국광학회 1999년도 제16회 광학 및 양자전자 학술발표회Proceedings of 16th Optics and Quantum Electronics Conference, 1999
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• pp.114-115
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• 1999