• 전자공학회논문지D
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• 제34D권4호
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• pp.73-78
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• 1997

A polymeric waveguide TE-pass polarier operating at wavelengths around 1.55.mu.m is realized by utilizing the birefringence induced by photoleaching at room temperature. To implement the polarizer, the photobleached waveguide supporting only TE mode is integrated in the middle of the etched rib waveguide that supports TE and TM modes. It has a simple structure and requires no high temperature process like poling. The measured polarization extinction ratio is about 21dB and the estimted excess loss is about 0.4dB.

• 한국가시화정보학회지
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• 제11권1호
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• pp.16-21
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• 2013

In this study, diffusion coefficients of 20 kDa FITC-dextran in 2% agarose gel with different cell concentrations were measured using fiberoptic-based fluorescence recovery after photobleaching technique. As increasing cell concentration suspended in agarose gel, the diffusion coefficients were decreased. The diffusion coefficient of agarose gel which contains $10{\times}10^6$ cells/ml was decreased to 11% that of in agarose gel without cells. The distribution of fluorescence dye in 3D scaffold was also simulated. The simulation result shows that the diffusion coefficient is more significant factor than the scaffold structure.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1995년도 춘계학술발표회 초록집
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• pp.60-68
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• 1995

This work wes performed to investigate the photocatalytic decolorization of waste water from textile industries. Methyl orange was used as a target dye with suspended Hombikat TiO$_2$ photocatalyst with a recirculating annular photoreactor. 1 wt % Pt-doped Hombikat thin film tubular reactor with parabolic reflector also wes usedin this experiment. The pH effect and flow rate effect on photobleaching of 0.012 g/l methyl orange solution, AtpH=3 Colour of methyl orange was completely bleached in 30 min with a 20 W UV lamp.

• Journal of the Optical Society of Korea
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• 제12권2호
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• pp.107-111
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• 2008

We demonstrated single-molecule fluorescence resonance energy transfer (FRET) from single donor-acceptor dye pair attached to a DNA with a setup based on a confocal microscope. Singlestrand DNAs were immobilized on a glass surface with suitable inter-dye distance. Energy transfer efficiency between the donor and the acceptor dyes attached to the DNA was measured with different lengths of DNA. Photobleaching of single dye molecule was observed and used as a sign of single-molecule detection. We could achieve high enough signal-to-noise ratio to detect the fluorescence from a single-molecule, which allows real-time observation of the distance change between single dye pairs in nanometer scale.

• 한국결정성장학회지
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• 제9권5호
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• pp.493-497
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• 1999

솔젤법을 사용하여 광촉매 $TiO_2$ 분말체를 제조하였으며 제조조건으로서 R값(물/알콕사이드 몰비), 열처리 온도, 미세구조로서 결정상, 물성으로서 비표면적과 입자크기의 상관관계를 조사하였으며 기능성으로 수용액상 염료의 광표백반응에 적용하여 광분해능을 극대화하기 위한 최적조건을 결정하였다.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4165-4168
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• 2012

Magnetic fluorescent silica nanotubes were fabricated using reverse micro-emulsions coupled with conventional sol-gel methods. Anodic aluminum oxide templates were used to separate spatially the magnetic and the fluorescent moieties on individual nanotubes and so prevent quenching of the fluorescence. C18 and fluorescent layers were deposited sequentially on silica. Magnetism was then obtained by the introduction of pre-made magnetic nanoparticles inside the nanotubes. The photo- and chemical stabilities of nanotubes were demonstrated through dye release and photobleaching tests. The produced nanotubes did not show fluorescence quenching upon the addition of the nanoparticles, an advantage over conventional spherical fluorescent magnetic nanoparticles. High photostability of nanotubes, magnetism and biocompatiblily make them potentially useful in bioanalysis.

• 분석과학
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• 제11권1호
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• pp.13-19
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• 1998

Allylthiourea를 포함하고 있는 광전기화학전지를 이용하여, 태양에너지 변환을 위한 염료 감응시, 감응전류는 광조사 시간 증가에 따라 증감 현상을 보였다. 광조사 전후 염료 용액을 분광학적으로 분석한 결과 감응제와 초감응제 사이의 침전형성 반응과 염료의 광표백 현상이 광전류 감소와 관련되어 있는 것으로 확인되었다.

• 한국광학회지
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• 제9권1호
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• pp.31-37
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• 1998

Acrylamide의 광중합(photopolymerization)반응에 의해 형성되는 acrylamide photopolymer를 제작하고 홀로그램 형성과정을 설명하였다. MB(methylene blue) 색소에 의한 빛의 흡수 및 표백과정과 TEA(triethanolamine)에 의해 라디칼중합을 하는 acrylamide 중합과정에 대해 자세히 논하였다. Beer-Lambert의 광화학 표백 모델(photochemical bleaching model)을 이용하여, photopolymer의 흡수곁수와 표백률상수(bleaching rate constant)를 구하였다. 그리고 acrylamide photopolymer의 홀로그램 특성에 기여하는 홑몸체(monomer)의 양과 회절효율과의 관계 및 노출량에 따른 회절효율을 측정하였다. 고분자 결정(polymer crystal)의 grain에 의한 산란효과와 정착(fixing)방법에 대해서도 논하였다.

• 통합자연과학논문집
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• 제14권4호
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• pp.147-154
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• 2021

A luminescent porous silicon sensor, whose surface was passivated with organic molecule via hydrosilylation under various conditions, has been researched to measure the photoluminescence (PL) stability of porous silicon (PSi). Photoluminescent PSi were synthesized by an electrochemical etching of n-type silicon wafer under the illumination with a 300 W tungsten filament bulb during the etching process. The PL of PSi displayed at 650 nm, which is due to the quantum confinement of silicon quantum dots in the PSi. To stabilized the photoluminescence of PSi, the hydrosilylation of PSi with silole molecule containg vinyl group was performed. Surface morphologies of fresh PSi and surface-modified PSi were obtained with a cold FE-SEM. Optical characterization of red photoluminescent silicon quantum dots was investigated by UV-vis and fluorescence spectrometer.

• 한국잡초학회지
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• 제31권4호
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• pp.323-329
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• 2011

색소체 transit 서열이 결여된 Bradyrhizobium japonicum ALA-S 유전자를 과발현하는 형질전환 벼의 광역학적 스트레스에 의해 유도되는 항산화반응을 조사하였다. $350{\mu}mol\;m^{-2}\;s^{-1}$ 의 높은 광 수준은 야생형 벼에 비교하였을 때 형질전환 계통인 C4와 C5의 quantum yield를 감소시켰다. 대조적으로, 높은 광수준 하에서 형질전환 계통 C4와 C5의 nonphotochemical quenching (NPQ) 수준은 야생형 계통과 낮은 광 수준 하의 형질전환 계통에 비해 높은 증가를 보여주었다. 형질전환 계통에서 높은 NPQ 수준은 xanthophyll인 zeaxanthin 수준의 증가와 밀접한 관련이 있었다. $150{\mu}mol\;m^{-2}\;s^{-1}$ 의 낮은 광 수준과 비교하였을 때 높은 광 수준에서 violaxanthin 수준이 야생형 벼에서 증가하였으나, 형질전환 C4와 C5 계통에서는 현저하게 감소하였다. 형질전환 벼에서 nonphotochemical energy dissipation과 광보호기작을 가진 xanthophyll 색소가 광역학적 피해를 조절하는데 결정적인 역할을 하는 것으로 생각되나, 이러한 기작이 광역학 스트레스를 극복하지는 못하였고 결과적으로 photobleaching 증상에 이르게 하였다.