• 제목/요약/키워드: Optical spectroscopy

검색결과 1,568건 처리시간 0.035초

Coherent Two-Dimensional Optical Spectroscopy

  • Cho, Min-Haeng
    • Bulletin of the Korean Chemical Society
    • /
    • 제27권12호
    • /
    • pp.1940-1960
    • /
    • 2006
  • Theoretical descriptions of two-dimensional (2D) vibrational and electronic spectroscopy are presented. By using a coupled multi-chromophore model, some examples of 2D spectroscopic studies of peptide solution structure determination and excitation transfer process in electronically coupled multi-chromophore system are discussed. A few remarks on perspectives of this research area are given.

Electronic and Optical Properties of amorphous and crystalline Tantalum Oxide Thin Films on Si (100)

  • Kim, K.R.;Tahir, D.;Seul, Son-Lee;Choi, E.H.;Oh, S.K.;Kang, H.J.;Yang, D.S.;Heo, S.;Park, J.C.;Chung, J.G.;Lee, J.C.
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
    • /
    • pp.382-382
    • /
    • 2010
  • $TaO_2$ thin films as gate dielectrics have been proposed to overcome the problems of tunneling current and degradation mobility in achieving a thin equivalent oxide thickness. An extremely thin $SiO_2$ layer is used in order to separate the carrier in MOSFETchannel from the dielectric field fluctuation caused by phonons in the dielectric which decreases the carrier mobility. The electronic and optical properties influenced the device performance to a great extent. The atomic structure of amorphous and crystalline Tantalum oxide ($TaO_2$) gate dielectrics thin film on Si (100) were grown by utilizing atomic layer deposition method was examined using Ta-K edge x-ray absorption spectroscopy. By using X-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy (REELS) the electronic and optical properties was obtained. In this study, the band gap (3.400.1 eV) and the optical properties of $TaO_2$ thin films were obtained from the experimental inelastic scattering cross section of reflection electron energy loss spectroscopy (REELS) spectra. EXAFS spectra show that the ordered bonding of Ta-Ta for c-$TaO_2$ which is not for c-$TaO_2$ thin film. The optical properties' e.g., index refractive (n), extinction coefficient (k) and dielectric function ($\varepsilon$) were obtained from REELS spectra by using QUEELS-$\varepsilon$(k, $\omega$)-REELS software shows good agreement with other results. The energy-dependent behaviors of reflection, absorption or transparency in $TaO_2$ thin films also have been determined from the optical properties.

  • PDF

Polarization Sensitive Low Coherence Interferometer를 이용한 Glucose 농도 측정 (Measurement of Glucose concentration using Polarization Sensitive Low Coherence Interferometer)

  • 이상원;김법민
    • 한국광학회:학술대회논문집
    • /
    • 한국광학회 2003년도 제14회 정기총회 및 03년 동계학술발표회
    • /
    • pp.128-129
    • /
    • 2003
  • 최근 수년간 polarimetry, Raman spectroscopy, near infrared (NIR) absorption spectroscopy, NIR scattering, optoacoustics 등의 방법을 통하여 비침습적으로 Glucose의 농도를 측정하려는 연구가 많이 시도되었다. 일반적으로 이들 방법은 sensitivity 와 signal-to-noise ratio가 매우 낮고 복잡한 알고리즘이 요구되어져 glucose 농도 측정에 한계가 있음이 드러났다. 본 연구에서는 polarization sensitive optical coherence tomography (PS-OCT)에 사용되는 polarization sensitive low coherence inter-ferometer (PS-LCI) 기법을 이용하여 비침습적으로 glucose의 농도 측정을 가능하게 하는 시스템 개발에 중점을 두었다. (중략)

  • PDF

비비드 옐로우 다이아몬드의 감별 방안 연구 (Identification for the Vivid Yellow Diamonds)

  • 송정호;윤유리;송오성
    • 한국세라믹학회지
    • /
    • 제49권6호
    • /
    • pp.493-497
    • /
    • 2012
  • We propose a new reliable, fast, and low cost identification method for similarly looking 0.3ct vivid yellow color of natural, HPHT treated, and synthesized diamonds. Conventional optical microscopy as well as low temperature PL(photoluminescence), FT-IR, UV-VIS-NIR, micro-Raman spectroscopy, and vibrating sample magnetometry(VSM) characterization were executed. We could not distinguish the natural diamonds from the treated or the synthesized stones with an optical microscopy, PL, FT-IR, and UV-VIS-NIR spectroscopy. However, we could identify the treated diamond with micro-Raman spectroscopy due to unique $1440cm^{-1}$ peak appearance. VSM revealed easily the synthesized diamond because of its ferromagnetic behavior. Our preliminary propose on employing the Micro-Raman spectroscopy and VSM might be suitable for identification of the similar looking vivid yellow colored diamonds.

Coherent Absorption Spectroscopy with Supercontinuum for Semiconductor Quantum Well Structure

  • Byeon, Ciare C.;Oh, Myoung-Kyu;Kang, Hoon-Soo;Ko, Do-Kyeong;Lee, Jong-Min;Kim, Jong-Su;Choi, Hyoung-Gyu;Jeong, Mun-Seok;Kee, Chul-Sik
    • Journal of the Optical Society of Korea
    • /
    • 제11권3호
    • /
    • pp.138-141
    • /
    • 2007
  • We suggest that supercontinuum can be used for absorption spectroscopy to observe the exciton levels of a semiconductor nano-structure. Exciton absorption spectrum of a GaAs/AlGaAs quantum well was observed using supercontinuum generated by a microstructrured fiber pumped by a femtosecond (fs) pulsed laser. Significantly narrower peaks were observed in the absorption spectrum from 11 K up to room temperature than photoluminescence (PL) spectrum peaks. Because supercontinuum is coherent light and can readily provide high enough intensity, this method can provide a coherent ultra-broad band light source to identify exciton levels in semiconductors, and be applicable to coherent nonlinear spectroscopy such as electromagnetically induced transparency (EIT), lasing without inversion (LWI) and coherent photon control in semiconductor quantum structures.

SiON 박막의 광학적 특성에 대한 연구 (The study of SiON thin film for optical properties.)

  • 김도형;임기주;김기현;김현석;성만영
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
    • /
    • pp.247-250
    • /
    • 2001
  • We studied optical properties of SiON thin-film in the applications of optical waveguide. SiON thin-film was grown in $300^{\circ}C$ by PECVD(plasma enhanced chemical vapor deposition) system. The change of SiON thin-film composition and refractive Index was studied as a function of varying $NH_3$ gas flow rate. As $NH_3$ gas flow rate was increased, Quantity of N and refractive index were increased at the same time. By the results, we could form the SiON thin-film to use of a waveguide with refractive index of 1.6. We analyzed the conditions of the thin-film with FTIR(fourier transform infrared) and OES (optical emission spectroscopy). N-H bonding($3390cm^{-1}$ ) can be removed by thermal annealing. And we could observe the SiH bonding state and quantity by OES analysis in $SiH_4$

  • PDF

SiON 박막의 광학적 특성에 대한 연구 (The study of SiON thin film for optical properlies)

  • 김도형;임기주;김기현;김현석;김상식;성만영
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2001년도 추계학술대회 논문집
    • /
    • pp.247-250
    • /
    • 2001
  • We studied optical properties of SiON thin-film in the applications of optical waveguide. SiON thin-film was grown in 300$^{\circ}C$ by PECVD(plasma enhanced chemical vapor deposition) system. The change of SiON thin-film composition and refractive Index was studied as a function of varying NH$_3$ gas flow rate. As NH$_3$ gas flow rate was increased, Quantity of N and refractive index were increased at the same time. By the results, we could form the SiON thin-film to use of a waveguide with refractive index of 1.6. We analyzed the conditions of the thin-film with FTIR(fourier transform infrared) and OES(optical emission spectroscopy). N-H bonding(3390cm$\^$-1/) can be removed by thermal annealing. And we could observe the SiH bonding state and quantity by OES analysis in SiH$_4$

  • PDF

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
    • /
    • 제34권4호
    • /
    • pp.436-442
    • /
    • 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.

  • PDF