• 한국가시화정보학회지
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• 제21권3호
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• pp.65-74
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• 2023

Compared to epifluorescence(EPI) microscopy which captures fluorescence from the entire depth of sample, total internal reflection fluorescence(TIRF) can selectively visualize only a single surface of it. TIRF uses a thin evanescent field generated by the total internal reflection of laser light on surface. However, conventional TIRF system are designed for total internal reflection to occur at the upper surface of sample, making them unsuitable for sessile droplet imaging. We designed a TIRF system suitable for a sessile droplet imaging by utilizing slide glass as a lightguide. We presented the details for constructing the TIRF system using a prism, slide glass, air slit, and optical trap. Then, we compared the TIRF with EPI by imaging the droplet with fluorescent particles during its drying process. As a result, TIRF allows us to distinctly visualize the drying pattern on the bottom surface of droplet.

• 전기학회논문지
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• 제56권9호
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• pp.1694-1698
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• 2007

This study suggests a new fluorescence microscope to observe micro-samples within fluorophore in a variety of biomedical fields including the fluorescence analysis of a biochip, such as a DNA micro-array. A fluorescence microscope is a device for irradiating light onto a micro-object, executing an excitation and fluorescence emission process. In this study, it adopts a total internal reflection fluorescence(TIRF) method to excite a whole micro-sample substrate different from an existing way which uses an evanescent wave resulting from a total internal reflection on the micro-sample surface. Suggested TIRF microscope can reduce optical noise and obtain images with higher sensitivity thus obtain precise information about the density, quantity, location, etc. of a flurophore, and can simultaneously process separate images even when plurality of fluorophores having different excitation and fluorescent wavelength ranges is distributed, thus easily obtain information about the fluorophores.

• 한국광학회지
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• 제7권2호
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• pp.112-119
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• 1996

TM 편광된 광자가 frustrated total internal reflection(FTIR) 구조에서 2차원적 터널링을 할 때 터널링에 소요되는 시간과 터널링되어 나오는 위치를 계산하였다. 이는 TM 편광된 광자의 FTIR 터널링 문제를 효과질량이 다른 이종 포텐셜 장벽을 터널링하는 전자의 문제로 변환시킴으로써 가능하였다. 계산된 결과를 TE 편광된 광자에 대한 경우와 비교하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.497-498
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• 2013

• Journal of the Optical Society of Korea
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• 제17권1호
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• pp.81-85
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• 2013

A miniaturized fluorescence detection system based on total internal reflection (TIR) configuration, which is applicable to detecting the presence of biological materials labeled with fluorescence dye in micro total analysis systems (${\mu}TAS$), is proposed. In conventional fluorescence testing and analysis devices, interference between the excitation light beam and the emitted light from dyes is unavoidable. This paper presents a fluorescence detection system based on TIR configuration that allows the excitation light beam and the emitted light to be spatially perpendicular to each other so as to minimize the interference where fluorescence emission is detected at the orthogonal angle to the excitation beam. We achieved the limit of detection of about 5 nmol/L with a high linearity of 0.994 over a wide range of 6-FAM mol concentration, being comparable to that in earlier studies.

• 한국전기전자재료학회논문지
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• 제28권10호
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• pp.676-681
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• 2015

Recently many studies being carried out to increase the light efficiency of LED. The external quantum efficiency of LED, generally the light efficiency, is determined by the internal quantum efficiency and the light extraction efficiency. The internal quantum efficiency of LED was already reached to more than 90%, but the light extraction efficiency is still insufficient compared with the internal quantum efficiency because the total internal reflection is generated in the interface between the LED chip and air. Thus, we studied about flip chip LED with PSS and performed the optical simulation which find more optimized PSS for flip chip LED to increase the light extraction efficiency. Decreasing of the total internal reflection and effect of diffused reflection according to PSS improved the light extraction efficiency. To get more higher the efficiency, we simulated flip chip with PSS that the parameters are arrangement, edge spacing, radius, height and shape of PSS.

• 대한전자공학회논문지SD
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• 제44권2호
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• pp.46-54
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• 2007

본 연구에서는 WDM 시스템의 집적화를 위해서 InP 기반의 신개념의 마이크로 링 공진기 필터를 제안하고, 제작을 통해서 그 특성을 측정 분석하였다. 전반사 미러가 삽입된 구조는 자동 정렬 (Self-Aligned) 공정을 통해서 구현 하였고, 측정된 전반사 미러의 손실은 한 개의 미러당 0.71 dB를 얻을 수 있었다. 마이크로 링 공진기의 결합기로는 다중모드 간섭기를 이용하여 빛이 광도파로를 따라 진행할 때 링으로 결합되는 파워를 높였다. 다중모드 간섭기의 주변을 깊게 에칭을 하여 간섭기의 길이와 폭을 $119{\mu}m$와 $9{\mu}m$로 하였다. 링 공진기 내부의 광도파로와 전반사 미러에서의 손실을 보상하기 위해서 링 공진기 내부에 길이가 $190{\mu}m$인 반도체 광 증폭기를 집적하였다. 이때 얻어진 FSR는 대략 1.333 nm (162 GHz)이고 소광비는 13 dB이다.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2725-2730
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• 2013

Single C-reactive protein (CRP) molecules, which are non-specific acute phase markers and products of the innate immune system, were quantitatively detected on a gold-nanopatterned biochip using evanescent field-enhanced fluorescence imaging. The $4{\times}5$ gold-nanopatterned biochip (spot diameter of 500 nm) was fabricated by electron beam nanolithography. Unlabeled CRP molecules in human serum were identified with single-molecule sandwich immunoassay by detecting secondary fluorescence generated by total internal reflection fluorescence (TIRF) microscopy. With decreased standard CRP concentrations, relative fluorescence intensities reduced in the range of 33.3 zM-800 pM. To enhance fluorescence intensities in TIRF images, the distance between biochip surface and CRP molecules was optimally adjusted by considering the quenching effect of gold and the evanescent field intensity. As a result, TIRF only detected one single-CRP molecule on the biochip the first time.

• 한국가시화정보학회지
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• 제3권1호
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• pp.3-19
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• 2005

Novel optical techniques are presented for three-dimensional tracking of nanoparticles; Optical Serial Sectioning Microscopy (OSSM) and Ratiometric Total Internal Reflection Fluorescent Microscopy (R-TIRFM). OSSM measures optically diffracted particle images, the so-called Point Spread Function (PSF), and dotermines the defocusing or line-of-sight location of the imaged particle measured from the focal plane. The line-of-sight Brownian motion detection using the OSSM technique is proposed in lieu of the more cumbersome two-dimensional Brownian motion tracking on the imaging plane as a potentially more effective tool to nonintrusively map the temperature fields for nanoparticle suspension fluids. On the other hand, R-TIRFM is presented to experimentally examine the classic theory on the near-wall hindered Brownian diffusive motion. An evanescent wave field from the total internal reflection of a 488-nm bandwidth of an argon-ion laser is used to provide a thin illumination field of an order of a few hundred nanometers from the wall. The experimental results show good agreement with the lateral hindrance theory, but show discrepancies from the normal hindrance theory. It is conjectured that the discrepancies can be attributed to the additional hindering effects, including electrostatic and electro-osmotic interactions between the negatively charged tracer particles and the glass surface.

• 한국광학회지
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• 제28권5호
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• pp.229-235
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• 2017

U형 구조의 SGDBR (Sampled Grating Distributed Bragg Reflector) 레이저 다이오드를 설계하고, 시간 영역 시뮬레이션 방법으로 해석하였다. U형 구조의 SGDBR 레이저 다이오드는 SGDBR, 능동, 수동, TIR (Total Internal Reflection) 거울 영역들로 이루어져 있어서, 각 영역들 간의 결합 손실의 영향을 면밀히 고려하여야 한다. 설계된 U형 SGDBR 레이저 다이오드의 파장 가변범위는 1525 nm에서부터 1570 nm로서 시뮬레이션을 통하여 확인하였다. 설계 튜닝 범위에서 완전한 레이저 다이오드 특성을 얻기 위해서는, 미러 영역에서의 손실은 약 2 dB 이하이고, 능동 및 수동 영역 간 butt 결합에서의 매질 간 굴절률 차이는 0.1 이하를 유지하도록 도파 구조가 설계되어야 한다.