• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 하계학술발표회
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• pp.108-109
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• 2000

현재 많은 종류의 레이저가 학술적으로나 산업계에서 다양하게 사용되고 있다. 그리고 그 중에서도 자외선 레이저의 필요성이 한층 강조되고 있는 시점이다. 사용되고 있는 자외선 레이저는 Eximer 레이저, Nd:YAG의 제3고조파, 다른 레이저로 펌핑한 색소 레이저등이 그 주류를 이루고 있다. 하지만 이들 레이저들은 값이 아주 고가이거나 그 출력이 매우 낮아 새로운 방식의 레이저를 요구하고 있다. 그래서 본 실험실에서는 여러 용도로 사용 가능한 펄스형 고출력 색소 레이저를 개발하고 있다. (중략)

• Journal of the Optical Society of Korea
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• 제8권2호
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• pp.79-82
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• 2004

High-efficiency mutually pumped phase conjugation (MPPC) has been realized in a BaTiO$_3$:Ce crystal in the bridge geometry. The laser source is a dye laser operating from 580 to 650 nm. We have observed that, with a beam ratio of 1, self-pumped phase conjugation (SPPC) appears and competes with MPPC at short wavelengths while it disappears at long wavelengths. When the beam ratio is slightly higher than 1, SPPC no longer occurs. Phase conjugate reflectivity near 500% has been obtained at a beam ratio of 70. Our experiments demonstrate that Ce-doped BaTiO$_3$crystals, which have already been found efficient in SPPC experiments, are also efficient for the generation of MPPC.

• 한국광학회:학술대회논문집
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• 한국광학회 1990년도 제5회 파동 및 레이저 학술발표회 5th Conference on Waves and lasers 논문집 - 한국광학회
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• pp.172-176
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• 1990

A high resolution picosecond absorption kinetic spectrometer utilizing dye emission and a streak camera is presented and compared with other methods of picosecond transient absorption measurements. Typical transient absorption and bleach recovery kinetics measured with this spectrometer are shown. Single wavelength transient absorption or ground state bleach recovery kinetics are determined on the basis of a single laser shot, so that the samples are relatively free frm decomposition by irradiation. Excellent kinetics may be obtained from the near UV to the near IR and are not subject to interference from luminescence of samples. The sensitivity of this spectrometer is very high and it is reasonably easy and convenient to set up and use.

• 한국광학회지
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• 제4권2호
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• pp.212-219
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• 1993

다중모드 레이저의 모드에 의해 광대역 CARS 분광에 생기는 모드 잡음을 줄이기 위하여 색소레이저의 증폭자발방출을 스톡스광으로 사용하여 CARS 분광을 측정하였다. 측정된 광대역 CARS 분광에 생기는 분광의 변조 폭에서 미량기체의 농도를 계산하는 새로운 방법을 제안하였으며, 변조 폭을 미랭기체의 농도와 기체 온도 변화에 대하여 수치적으로 계산하고 이를 분석하여, 계산된 변조 폭을 농도와 온도에 대한 함스로 기술하였다. 이러한 방법을 Ar과 미량의 CO 혼합기체를 셀에 넣고 CO 농도를 측정하여 검정하였으며, 실제로 응용하여 대향류 버너의 불꽃 속의 CO 농도 분포측정에 응용하였다.

• 대한의용생체공학회:의공학회지
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• 제14권1호
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• pp.17-22
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• 1993

Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided intro two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weights). The other group received no Photofrin E Mice from both groups were irradiated for approximately 15 minutes at 100,300, or $500{\;}mW/\textrm{cm}^2$ with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photofrin II increased surface temperature by at least 40% and the temperature rise due to $300{\;}mW/\textrm{cm}^2$ irradiation exceeded values for hyperthermia. Lights and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2001년도 제22회 KOSCI SYMPOSIUM 논문집
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• pp.133-138
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• 2001

In this study, quantitative nitric oxide concentration distributions are investigated in the laminar nonpremixed $H_2/N_2$ flames by laser-induced fluorescence (LIF). The measurements are taken in flames for different $N_2$ dilution ratios varying from 20${\sim}$80%, and fuel now rate is fixed as lslpm. The NO A-X (0,0) vibrational band around 226 nm is excited using a XeCl excimer-pumped dye laser. We applied same excitation line used in $CH_4$ premixed flame. Overall, NO concentration was rapidly decreased with $N_2$ addition and we could not measure the concentration any longer for $N_2$ dilution above 80%.

• 한국분무공학회지
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• 제6권3호
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• pp.1-7
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• 2001

In this study, quantitative measurement of nitric oxide concentration distributions visualization were investigated in the laminar $CH_4/O_2N_2$ nixed flame by Planar laser-induced fluorescence(PLIF). The NO A-X (0,0) vibrational band around 226nm was excited using a XeCl excimer-pumped dye laser. Selecting an appropriate NO transition minimizes interference from Rayleigh scattering and $O_2$ fluorescence. The measurements were taken in $CH_4/O_2N_2$ premixed flame with equivalence ratios varying from $1.0{\sim}1.6$, and a fixed flow rate of 3slpm. NO was found to produce primarily between an inner premixed and an outer nonpremixed flame front, and total NO concentration is raised when equivalence ratios increase. These results suggest that prompt NO is likely to contribute to MO formation in $CH_4/O_2N_2$ premixed flame. Furthermore, this trend was well matched with previous works.

• 한국분무공학회지
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• 제7권4호
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• pp.42-49
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• 2002

In this study, quantitative measurement of nitric oxide concentration distributions were investigated in the laminar CH4/O2/N2 premixed flame by laser-induced fluorescence (LIF). The NO A-X (0,0) vibrational band around 226nm was excited using a XeCl excimer-pumped dye laser. Selecting an appropriate NO transition minimizes interference from Rayleigh scattering and O2 fluorescence. The measurements were taken in CH4/O2/N2 premixed flame with equivalence ratios varying from $1.0{\sim}1.6$, and a fixed flowrate of 5slpm. NO was found to produce primarily between an inner premixed and an outer nonpremixed flame front, and total NO concentration is raised when equivalence ratios increase. These results suggest that prompt NO is likely to contribute to NO formation in CH4/O2/N2 premixed flame. Furthermore, this trend was well matched with previous works.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.156-161
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• 2000

In this study, quantitative nitric oxide concentration distributions are investigated in the post-flame zone of laminar premixed $CH_4/O_2/N_2$, flames by laser-induced fluorescence (LIF). The measurements are taken in flames for different equivalence ratios varying from $0.8{\sim}1.4$, and flow rate is fixed as 5slpm. The NO A-X (0,0) vibrational band around 226 nm is excited using a XeCl excimer-pumped dye laser. Selecting an appropriate NO transition minimizes interferences from Rayleigh scattering and $O_2$ fluorescence. NO concentration is rised when equivalence ratios increase at different vertical distances form nozzle tip. In any case, the maximum NO concentration reaches the maximum in reaction zone.

• 대한기계학회논문집B
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• 제33권5호
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• pp.311-317
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• 2009

Due to extremely small device size and velocity scale, mixing in microchannel take place very slowly by way of molecular diffusion transport. Mixing enhancement becomes a central issue in microfluidics for biomedical and chemical applications. In this work, The optimization results and validation through experiment and fabrication. In this efficient micromixer design, it is essential to evaluate mixing efficiency with good precision. Mixing efficiency for Y-channel micromixer is measured by fluorescence intensity using LIF(Laser Induced Fluorescence) Confocal Microscope. The Y-channel micromixers are fabricated with polydimethylsiloxane(PDMS). Nile Blue A is injected into the micromixer as a fluorescence dye for measuring of fluorescence intensity by He/Ne laser. Throughout the experiments and computer simulation, accurate mixing efficiency evaluation process for a PDMS Y-channel micromixer is established.