• 제목/요약/키워드: Nonlinear spectroscopy

검색결과 74건 처리시간 0.024초

Experimental Determinations of Coherent Multidimensional Vibrational Spectroscopy

  • Besemann, Daniel;Condon, Nicholas;Meyer, Kent;Zhao, Wei;Wright, John C.
    • Bulletin of the Korean Chemical Society
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    • 제24권8호
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    • pp.1119-1125
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    • 2003
  • Coherent multidimensional vibrational spectroscopy is a new technique for establishing correlations between features in vibrational spectra that are caused by intra- and intermolecular interactions. These interactions cause cross-peaks between vibrational transitions that reflect the coupling. In this paper, we use Doubly Vibrationally Enhanced Infrared Spectroscopy (DOVE-IR) and DOVE-Raman processes to obtain coherent two dimensional vibrational spectra. The spectra are fitted to obtain the dephasing rates and third order susceptibilities $(χ^{(3)})$ for the nonlinear processes. We show that the DOVE $χ^{(3)}$ values are directly related to the molar absorptivities and Raman $χ^{(3)}$. We then use these relationships to obtain estimates for the $χ^{(3)}$ of the stimulated photon echo and $χ^{(5)}$ of the six wave mixing spectroscopies, respectively. We also predict the ratio of the cascaded four wave mixing signal to the six wave mixing signal.

CuCl 미립자가 분산된 비선형 광학유리의 제조와 비선형 광특성: III. CuCl 반도체 미립자의 Bimodal 분포 특성과 온도에 따른 광흡수도 (Preparation and Nonlinear Optical Properties of CuCl-doped Nonlinear Optical Glasses : III. Bimodal Distribution of CuCl Nanocrystals and Temperature Dependent Optical Absorption Spectra)

  • 윤영권;한원택
    • 한국세라믹학회지
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    • 제34권4호
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    • pp.436-442
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    • 1997
  • The bimodal distribution of CuCl nano-crystals precipitated in alumino-borosilicate glass matrix (30SiO2-45B2O3-7.5Al2O3-7.5Na2O-7.5CaO-2.5GeO2(mole %)) was investigated by TEM and the temperature dependent optical spectroscopy. Two types of CuCl particles with different size were observed by TEM and it was confirmed by the splitting of Z3 absorption peak at low temperature and the occurrence of deflection point in the optical spectra with temperature.

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Nonlinear Optical Spectroscopy

  • Van Stryland, E.W.;Hales, J.;Belfield, K.;Hagan, D.J.
    • 한국광학회:학술대회논문집
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    • 한국광학회 2004년도 제15회 정기총회 및 동계학술발표회
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    • pp.6-7
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    • 2004
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프리스트레스트 보의 콘크리트 응력 수준 평가를 위한 비선형 초음파 공진 기법의 적용 (Adoption of Nonlinear Resonant Ultrasonic Spectroscopy for the Evaluation of Stress State on Concrete in Prestressed Beam)

  • 김규진;곽효경
    • 한국전산구조공학회논문집
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    • 제30권3호
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    • pp.215-222
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    • 2017
  • 프리스트레스트 보의 인장력 변화에 따른 콘크리트 응력 수준을 평가하기 위하여, 초음파를 이용하는 기존의 방법보다 개선된 비선형 초음파 공진 기법의 도입을 제안하였다. 이는 동일하게 초음파를 사용하는 선형의 기법보다 월등히 높은 민감도를 보이므로 초기 상태의 응력 평가에도 유리하다. 비선형 초음파 공진 기법은 초음파 통과시 매질 상태에 따른 공진 주파수의 변화의 정도로부터 계산되는 비선형 인자의 값을 측정하며, 측정 결과는 콘크리트의 응력 상태와도 밀접한 연관을 갖는다. 본 연구에서는 유압 펌프를 통한 인장력 작용에 따른 비선형 인자의 측정을 수행함으로써 두 인자 사이에 밀접한 연관성이 있음을 확인하고, 반복적인 하중 이력의 작용이 비선형 인자의 변화에 미치는 영향을 분석하였다. 추가적으로, 선형 초음파 전파 속도 측정 결과를 비교하여 제안한 방법의 민감도를 검증하였다. 측정 결과를 통해 프리스트레스트 보의 콘크리트 응력 수준 평가를 위한 비선형 초음파 공진 기법의 적용 가능성을 확인하였다.

CuCl 미립자가 분산된 비선형 광학유리의 제조와 비선형 광특성: I. 제조와 미세조직 및 광특성 (Preparation and Nonlinear Optical Properties of CuCl-doped Nonlinear Optical Glasses: I. Preparation, Microstructure, and Optical properties)

  • 윤영권;한원택
    • 한국세라믹학회지
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    • 제34권4호
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    • pp.420-428
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    • 1997
  • Alumino-borosilicate glasses containing nano-sized CuCl crystals for nonlinear optical application were prepared by the melting and precipitation process, and structural and optical properties were investigated by using XRD, TEM, SAXS, and optical spectroscopy. the average radius of the precipitated CuCl particles was about 2 nm. The blue shift of Z3 resonance peak with decreasing the precipitated CuCl particles size was found and the radius increased with decreasing the glass transition temperature of the matrix glass and with increasing the temperature and duration time of the precipitation heat treatment.

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재료의 미세결함 검출을 위한 레이저 공명 초음파 분광(Laser-RUS)시스템 개발 (Development of Laser-Based Resonant Ultrasound Spectroscopy(Laser-RUS) System for the Detection of Micro Crack in Materials)

  • 강영준;김진수;박승규;백성훈;최낙정
    • 한국정밀공학회지
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    • 제27권1호
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    • pp.41-48
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    • 2010
  • Non-contacting, laser-based resonant ultrasound spectroscopy (L-RUS) was applied to characterize the microstructure of a material. L-RUS is widely used by virtue of its many features. Firstly, L-RUS can be used to measure mechanical damping which related to the microstructural variations (grain boundary, grain size, precipitation, defects, dislocations etc). Secondly, L-RUS technology can be applied to various areas, such as the noncontact and nondestructive quality test for precision components as well as noncontact and nondestructive materials characterization. In addition, L-RUS technology can measure the whole field resonant frequency at once. In this paper, we evaluated material characteristics such as resonant frequency, nonlinear propagation characteristic through the development of Laser-Based Resonant Ultrasound spectroscopy (Laser-RUS) System for the detection of Micro Crack in Materials.

근적외분광분석법을 이용한 생쥐꼬리에서의 비침습 혈당 정량시 장기간 측정에 따른 변이 요인의 보정 (Compensation of Variation from Long-Term Spectral Measurement for Non-invasive Blood Glucose in Mouse by Near-Infrared Spectroscopy)

  • 백주현;강나루;우영아;김효진
    • 약학회지
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    • 제48권3호
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    • pp.177-181
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    • 2004
  • Non-invasive blood glucose measurement from mouse tail was performed by near-infrared (NIR) spectroscopy. Three groups; normal, type I diabetes (insulin dependent diabetes mellitus, IDDM), type II diabetes (non-insulin dependent diabetes mellitus, NIDDM) group, were studied over a 10 weeks period with the collection of near-infrared (NIR) spectra. Spectral variations from long-term measurement (10 weeks) from dramatic and nonlinear changes in the optical properties of the live tissue sample were compensated by chemometrics techniques such as principle component analysis (PCA) and partial least squares (PLS) regression. The effect from mouse body temperature changes on NIR spectral data was also considered. This study showed that the compensation of variations from long-term measurement and temperature changes improved calibration accuracy of non-invasive blood glucose measurement.