• Korean Journal of Optics and Photonics
• /
• v.10 no.2
• /
• pp.95-101
• /
• 1999

We have studied the 1.54$\mu\textrm{m}$ forward and backward stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SRS) for various $CH_4$pressures by 1.06$\mu\textrm{m}$ Q-switched Nd:YAG laser pumping under a repetition rate of Hz in single pass. We obtained that the output of backward SRS was more efficient than that of the forward SRS. The output energy and conversion efficiency of forward and backward SRS were higher than those of SBS since SRS is a steady state, but SBS is a transient state. In a $CH_4$gas uncirculating system, the output energy of the backward SRS and SBS were reduced the about 47% due to a thermal heating of $CH_4$medium in a focusing region for a repetition rate of 5 Hz. But, the output energy of forward SRS was slightly enhanced by about 8.5% due to the increase of the undepleted pump beam in the backward SRS generation. Inthe Raman half resonator using a dichromatic focusing lens, the conversion efficiency of SRS was more than 37% for a input pump laser energy of 40 mJ.

• Proceedings of the Optical Society of Korea Conference
• /
• 2002.07a
• /
• pp.20-21
• /
• 2002

결맞는 두 개의 레이저 즉 결합광과 조사광을 이용하고 라만 공진 조건을 만족할 때, 특별한 조건하에서 조사광의 흡수가 급격히 줄어드는 검은공진(dark resonance)현상이 일어난다. 이러한 현상은 굴절률 변천에 기인하여 밀도반전없는 레이저 등 비선형 광학과 고분해 분광학, 양자광학 등 많은 분야에 응용되고 있다. (중략)

• Korean Journal of Microbiology
• /
• v.53 no.2
• /
• pp.71-78
• /
• 2017

Raman microspectroscopy is a promising tool for microbial analysis at single cell level since it can rapidly measure the cell materials including lipids, nucleic acids, and proteins by measuring the inelastic scattering of a molecule irradiated by monochromatic lights. Using Raman spectra provides high specificity and sensitivity in classification of bacteria at the strain level. In addition, a Raman approach coupled with stabled isotope such as $^{13}C$ and $^2H$ is able to detect and quantify general metabolic activity at single cell level. After bacterial detection process by Raman microspectroscopy, interested unculturable cell sorting and single cell genomics can be accomplished by combination with optical tweezer and microfluidic devices. In this review, the characteristics and applications of Raman microspectroscopy were reviewed and summarized in order to provide a better understanding of microbial analysis using Raman spectroscopy.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.94.1-94.1
• /
• 2016

레이저 진단은 플라즈마 진단법 중 가정 정확한 진단법으로 알려져 있다. 특히 진단이 까다로운 고밀도, 자기장, 고압 환경에서도 그 측정 결과가 신뢰성 있다고 잘 알려져 있다. 본 특별 심포지엄에서는 중 성종을 측정 할 수 있는 레일레이 산란과 자유 전자를 측정 할 수 있는 톰슨 산란, 그리고 분자를 측정할 수 있는 라만 산란을 중심으로 발표 할 것이다. 또한 특정 준위를 갖는 원자 및 분자의 거동을 측정할 수 있는 레이저 유도 형광에 대해서도 간단히 발표 할 것이다. 그밖에 레이저 진단의 종류, 원리 등을 설명 하고 한국표준과학연구원에서 이루어 진고 있는 연구 결과에 대해 발표 할 것이다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.05a
• /
• pp.80-83
• /
• 2005

$Nd:YVO_4$ 연속발진 레이저 (CW laser)를 이용하여 다결정실리콘 (CLC poly-Si)을 제작하였다. CLC 다결정 실리콘의 결정화 영역은 결정립 크기에 따라 SLC(Sequential Lateral Crystallization) 영역, SLG(Super Lateral Grain) 영역 및 Small Grain 영역으로 구분된다. 레이저를 중첩스캔 하여 제작한 CLC 다결정실리콘의 경우, 레이저 스캔 경계에서 단결정립이 형성됨을 SEM으로 확인하고, CLC 다결정실리콘의 결정성을 XRD와 라만 스펙트럼(Raman spectrum)을 이용하여 조사하였다.

• Proceedings of the Optical Society of Korea Conference
• /
• 2005.02a
• /
• pp.16-17
• /
• 2005

• New Physics: Sae Mulli
• /
• v.69 no.10
• /
• pp.1107-1114
• /
• 2019

Producing extremely stable high temperature and pressure condition is crucial in order to synthesize novel materials with various functions and to investigate their static and dynamic properties. Already a high pressure in the Mbar range, which is necessary to make novel materials, can be acquired by using a Diamond Anvil Cell (DAC), In this study, a laser-heating system combined with the DAC was designed and installed using two 1064-nm, 100-W fiber lasers on different sides of the DAC to heat the sample and three spectrometers to measure the temperature, pressure, and Raman spectra. A stainless-steel gasket, which is generally used as a sample chamber in high-pressure experiments, was heated to make a thermal radiation source, and the temperature of the heated gasket was obtained by measuring the spectrum of the radiation. By applying this technique, we were able to make various materials and to investigate their physical properties under extreme conditions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.158-161
• /
• 2012

Raman Laser Radar system for the measurements of aerosol and water vapor concentration is developed. As a transmitting system, Nd:YAG laser with 3rd harmonic Generator and beam expander are used. The wavelength of transmitting laser is 355 nm. The receiving system is consists of 500 mm telescope, 3-channel Raman spectrometer, PMT, and signal processing module. The wavelengths of received signals are 355 nm. 387 nm, and 408 nm 이다. The measurable altitude of this system is about 3~4 km with spatial resolution of 100~200 m.

• Korean Journal of Remote Sensing
• /
• v.35 no.6_3
• /
• pp.1187-1195
• /
• 2019

We, for the first time, developed a Raman lidar system which can remotely detect surface CO₂ volume mixing ratio (VMR). The Raman lidar system consists of the Nd: YAG laser of wavelength 355 nm with 80 mJ, an optical receiver, and detectors. Indoor CO₂ cell measurements show that the accuracy of the Raman lidar system is calculated to be 99.89%. We carried out the field measurement using our Raman lidar at Pukyong National University over a seven-day period in October 2019. The results show good agreement between CO₂ VMRs measured by the Raman lidar (CO₂ Raman Lidar) and those measured by in situ instruments (CO₂ In situ) which located 300 m and 350 m away from the Raman lidar system. The correlation coefficient (R), mean absolute error (MAE), and root mean square error (RMSE) between CO₂ In situ and CO₂ Raman Lidar are 0.67, 2.78 ppm, and 3.26 ppm, respectively.

• Polymer Science and Technology
• /
• v.15 no.2
• /
• pp.228-233
• /
• 2004

본 기고부분에서는 레이저 라만 분광법을 이용하여 나노입자에 흡착된 자기조립박막의 구조를 밝히고 응용성을 모색하는 일을 소개하고자 한다 Au 나노입자는 최근 재료과학과 의학 및 생물학에서 그 쓰임의 폭이 넓어지고 있다. 나노입자가 처음 사용된 예들 중에 가장 잘 알려진 것은 고대 로마 시대의 Lycurgus 컵에 기인한다고 한다. 컵 안에 함유된 미량의 은이나 금 나노입자에 의해서 반사했을 때와 투과할 때의 빛깔이 다르게 보이며 이러한 성질은 중세건축물의 스탠드 글라스에 이용되어 왔다. 근대적인 의미에서 Au 콜로이드의 수용액이 작은 미세입자가 분산되어 있다고 생각한 사람은 전기화학의 창시자라 할 수 있는 영국의 Faraday라 할 수 있다.(중략)