• 센서학회지
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• 제28권5호
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• pp.305-310
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• 2019

The purpose of this study is to classify the concentration of HbA1c (glycosylated hemoglobin), which is an indicator in the management of accurate blood glucose level in diabetic patients, using a non-invasive optical property measurement method. To measure the optical properties of HbA1c, the optical source uses LEDs and laser diodes of 400 nm in the visible region and 1450 nm in the nearinfrared region using thermopile to detect the Raman scattering intensity. An HbA1c control solution was used. As a result, the optical properties of 5% (normal) and 9% (abnormal) HbA1c control solutions showed specificity in which the output values were reversed at 850 nm and 950 nm, respectively. This property was applied to distinguish between normal and abnormal values in diabetes. In addition, considering tissue penetration depths for non-invasive measurements, two wavelengths were determined to be effective in distinguishing the concentrations of HbA1c control solutions at 5%, 7%, and 9%.

• 한국광학회지
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• 제35권2호
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• pp.71-80
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• 2024

이산화탄소 원격 계측을 위한 라만 라이다 장치를 개발하기 위해 라만 라이다 장치의 소형화를 진행하고, 이에 스캐닝 장치를 결합하여 라만 라이다 시스템을 개발하였다. 개발한 시스템의 성능 검증을 위하여 가스 챔버를 약 87 m 거리에 위치시킨 후, 이산화탄소의 농도 변화에 따른 라만 산란 신호를 계측하였다. 그 결과 개발된 라만 라이다 장치를 이용하였을 때 약 0.67-40 vol% 사이의 농도에서 높은 선형성을 나타냄을 확인하였다.

• 천문학회보
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• 제42권2호
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• pp.86.4-87
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• 2017

Symbiotic stars are binary systems composed of a hot white dwarf and a mass losing giant. Many symbiotic stars are known to exhibit broad wings around Balmer emission line. We show high resolution spectra of S-type symbiotic stars, Z Andromedae and AG Draconis, obtained with the ESPaDOnS and the 3.6 m Canada-France-Hawaii Telescope, in which we find prominent broad wings around Balmer lines. We adopt Monte-Carlo technique to consider two types of wing formation mechanisms, which are Thomson scattering by free electron in H II region and Raman scattering by atomic hydrogen in H I region. We find that Thomson wings of $H{\alpha}$ and $H{\beta}$ have the same widths in the Doppler space due to the cross section independent of wavelength. In contrast, Raman $H{\alpha}$ wings are 3 times broader widths than $H{\beta}$ counterparts, which is attributed to the different cross sections and branching ratios. Our CFHT data show that $H{\alpha}$ wings of Z Andromedae and AG Draconis are broader than $H{\beta}$ wings, lending strong support to the Raman scattering origin of Balmer wings in these objects.

• ETRI Journal
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• 제29권6호
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• pp.779-784
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• 2007

In this paper, we report the experimental results of a hybrid wideband fiber amplifier. The amplifying medium is a concatenated hybrid fiber consisting of Er-doped fiber (EDF) and dispersion compensating fiber (DCF). The gain mechanisms are based on stimulated emission in the EDF and stimulated Raman scattering (SRS) in the DCF. Since we simultaneously use optical amplification by the two processes, the gain bandwidth is easily expanded over 105 nm by a two-tone pumping scheme. Using an experimental setup constructed with a hybrid structure of EDF-DCF-EDF, we analyzed the spectral behavior of amplified spontaneous emission for pumping powers. We achieved an optical gain of over 20 dB in the wavelength range from 1,500 to 1,600 nm under optimized pumping conditions to make the spectral gain shape flat.

• Journal of the Optical Society of Korea
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• 제14권3호
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• pp.209-214
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• 2010

The Raman shift of water vapor is 3657 $cm^{-1}$, and this Raman signal can be easily separated from other Raman signals or elastic signals. However, it is difficult to make simultaneous Raman measurements on the three phases of water, namely, ice water, liquid water, and water vapor. This is because we must consider the overlap between their Raman spectra. Therefore, very few groups have attempted to make Raman simultaneous measurements even on two elements (water vapor and liquid water, or water vapor and ice water). We have made an effort to find three characteristic Raman wavelengths that correspond to the three phases of water after measuring full Raman spectra of water on particular days that are rainy, snowy or clear. Finally, we have found that the 401-nm, 404-nm, and 408-nm wavelengths are the most characteristic Raman wavelengths that are representative of the water phases when we are using the 355-nm laser wavelength for making measurements.

• 한국광학회지
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• 제25권1호
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• pp.1-7
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• 2014

구름에서의 다중산란 효과는 Mie 산란현상을 이용하는 탄성산란 라이다에서 그 해를 구하는데 있어서, 매우 중요한 오차요인으로 작용하기 때문에 이 효과를 보정하는 것은 그 자체만으로도 매우 중요하다. 이를 위하여 구름에서 다중산란되는 현상을 Monte Carlo 방법으로 계산하였으며, 이 결과를 적용하여 물방울 구름의 총량과 유효입자크기를 추출하는 방법을 제안하였다. 구름의 유효입자 크기가 $2.5{\mu}m$ 이하일 경우엔 355 nm나 1064 nm에서 얻은 두 파장의 소광계수로 쉽게 그 값들을 구할 수 있음을 알 수 있었다. 크기가 큰 경우엔 라이다 신호의 안정화된 선형편광도가 유효입자크기, 총량, 그리고 소광계수와 관련이 있음을 알 수 있었으며, 이 관계를 통하여 큰 입자의 경우에도 라만 라이다와 편광 라이다를 이용한다면 유효입자크기와 총량을 구할 수 있다는 것을 알 수 있었다.

• 한국항공우주학회지
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• 제45권6호
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• pp.523-530
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• 2017

높은 에너지의 레이저가 조사되면 레이저 삭마 현상을 일으키고, 결과적으로 플라즈마가 물질에 따라 특정한 파장의 빛을 방출하는 레이저 유도 파괴 분광법(LIBS, Laser-Induced Breakdown Spectroscopy)과 빛은 산란 현상에 대해 분자 간 혹은 분자 내의 회전 및 진동 운동을 측정하는 라만 분광법은 높은 정확도와 실시간 분석이 가능하다는 점, 원거리 검출이 가능하다는 장점들을 기반으로 우주 탐사 기술로써 주목을 받고 있다. 본 연구에서는 레이저 분광법을 활용하여 토양 성분의 변화에 따른 레이저 스펙트럼의 경향성을 파악하고, 이를 기반으로 2차원 화학적 분포도 실험을 진행하였다. 또한 화성(4-7 torr)과 달의 대기(<1 torr) 환경을 레이저 실험 환경 내에 구축하여 인공적인 우주 환경에서 LIBS와 라만 분광법을 활용하여 토양 성분의 변화에 따른 LIBS와 라만 분광법을 통한 계측이 가능함을 증명하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.220-222
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• 2005

We can classify two cases in a way to observe an atom of gas state or a molecule using the laser. First case is way to use dispersion phenomenon like Rayleigh scattering, Thomson scattering, Mie scattering, Raman Scattering. And Second case is a way to use change phenomenon like a LAS (Laser Absorption Spectroscopy), LIF (Laser Induced Fluorescent). In this paper, we have measured the meta-stable density and the distribution by using a LAS method in Xe discharge lamp. The laser absorption spectroscopy (LAS) is useful to investigate the behavior of such species. The xenon atoms in the $1S_4$ and $1S_5$ generate excited $Xe^*$(147nm) and $Xe_{2}^*$(173nm) dimers in Xe plasma. It is found that the intensity of VUV 147nm emission is proportional to that of the IR 828nm emission, and the VUV 173nm emission is roughly proportional to that of the IR 823nm emission. The laser is used CW laser that consist of AlGaAs semiconductor and energy level is used 823.16nm wavelength. We measured signal of monochrometer from the lamp center while will change a discharge electric current by 6mA in 3mA and calculated meta-stable state density of a xenon atom through a measured value.

• Journal of the Optical Society of Korea
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• 제18권5호
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• pp.551-557
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• 2014

In this study, we demonstrated multimodal nonlinear optical (NLO) microscopy integrated simultaneously with two-photon excitation fluorescence (TPEF), second-harmonic generation (SHG), and coherent anti-Stokes Raman scattering (CARS) in order to obtain targeted cellular and label-free images in an immunofluorescence assay of the atherosclerotic aorta from apolipoprotein E-deficient mice. The multimodal NLO microscope used two laser systems: picosecond (ps) and femtosecond (fs) pulsed lasers. A pair of ps-pulsed lights served for CARS (817 nm and 1064 nm) and SHG (817 nm) images; light from the fs-pulsed laser with the center wavelength of 720 nm was incident into the sample to obtain autofluorescence and targeted molecular TPEF images for high efficiency of fluorescence intensity without cross-talk. For multicolor-targeted TPEF imaging, we stained smooth-muscle cells and macrophages with fluorescent dyes (Alexa Fluor 350 and Alexa Fluor 594) for an immunofluorescence assay. Each depth-sectioned image consisted of $512{\times}512$ pixels with a field of view of $250{\times}250{\mu}m^2$, a lateral resolution of $0.4{\mu}m$, and an axial resolution of $1.3{\mu}m$. We obtained composite multicolor images with conventional label-free NLO images and targeted TPEF images in atherosclerotic-plaque samples. Multicolor 3-D imaging of atherosclerotic-plaque structural and functional composition will be helpful for understanding the pathogenesis of cardiovascular disease.