• Title/Summary/Keyword: Optical absorption

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Three-Dimensional Microfabrication with Nano Resolution Using Two-Photon Absorption of Femto-Second Laser (극초단 펄스 레이저의 이광자흡수를 이용한 나노분해능의 3차원 마이크로 구조 제작)

  • Yi, Shin-Wook;Lee, Seong-Ku;Kong, Hong-Jin;Park, Sang-Hu;Jeong, Chang-Gyun;Taewoo Lim;Yang, Dong-Yol
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.64-65
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    • 2003
  • Stereo-lithography using the two photon absorption(TPA) makes micro structures with great resolution. The technique is applied to correcting photomask, 3-D photonic crystal, 3-D optical storage, 3-D lithography and so on. In contrast to a conventional stereo-lithography with single-photon absorption which has a size problem caused by the geometrical diffraction limit, the stereo-lithography with TPA has no size limit. (omitted)

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Optical and electrical properties of $C_{22}$-quinolinium(TCNQ) langmuir-glodgett films depending on the annealing temperatures ($C_{22}$-quinolinium(TCNQ) langmuir-blodgett 박막의 열처리 온도에 따른 광학적 및 유전특성)

  • 홍언식;유덕선;김태완
    • Electrical & Electronic Materials
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    • v.8 no.4
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    • pp.458-463
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    • 1995
  • The optical and electrical properties of $C_{22}$-Quinolinium(TCNQ) Langmuir-Blodgett films have been studied depending on the annealing temperatures. The optimal properties were investigated using UV/visible(300-800[nm]) absorption spectra and FTIR(Fourier-transformed- infrared) absorption measurements. The electrical properties were investigated in a frequency range of 10[Hz]-13[MHz]. The UV/visible absorption spectra at room temperature show that there are four characteristic peaks at 320, 380, 494 and 678[nm]. These absorption peaks decrease very rapidly above the annealing temperature of 180[.deg. C], which is due to a structural change of TCNQ. The FTIR absorption measurements strongly support the result of the UV/visible absorption spectra, because the absorption peak of TCNQ- at 2181[$cm^{-1}$ /] also decreases above 140[.deg. C]. The frequency-dependent dielectric constant shows that there is a dielectric dispersion near 1[MHz] which is due to an orientational polarization of the molecules inside the film. The overall frequency-dependent dielectric constant is higher near 80[.deg. C]. It may be due to a softness of the alkyl chains.s.

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Growth and optical properties of undoped and Co-doped CdS single crystals (CdS 및 CdS:Co2+ 단결정의 성장과 광학적 특성)

  • Oh, Gum-kon;Kim, Nam-oh;Kim, Hyung-gon;Hyun, Seung-cheol;Park, hjung;Oh, Seok-kyun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.51 no.3
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    • pp.137-141
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    • 2002
  • CdS and $CdS:Co^{2+}$ single crystals were grown by CTR method using iodine as transport material. The grown single crystals have defect chalcopyrite structure with direct band gap. The optical energy band gap was decreased according to add of Co-impurity. We can observed the Co-impurity optical absorption peaks assigned to the $Co^{2+}$ ion sited at the $T_d$ symmetry lattice and we consider that they were attributed to the electron transitions between energy levels of ions.

Preparation and Nonlinear Optical Properties of CuCl-doped Nonlinear Optical Glasses : II. Nonlinear Optical Properties (CuCl 미립자가 분산된 비선형 광학유리의 제조와 비선형 광특성: II. 비선형 광특성)

  • 윤영권;한원택;이민영
    • Journal of the Korean Ceramic Society
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    • v.34 no.4
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    • pp.429-435
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    • 1997
  • The third order nonlinear optical susceptibilities, {{{{ chi }}(3), of the CuCl doped alumino-borosilicate glasses were measured by the two beam configuration DFWM method and the absorption saturation method, and the measured {{{{ chi }}(3) values were about 10-8 esu in both methods. The response time was estimated to be about 105ps from the time decay curve of the luminescence spectra obtained by time-correlated single-photon counting (TCSPC) method.

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Synthesis and Characterization of Fluorinated Poly(phenylmaleimide-co-pentafluorophenylmaleimide) for Optical Waveguides

  • Choi, Jongwan;Oh, Jin-Woo;Kim, Nakjoong
    • Bulletin of the Korean Chemical Society
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    • v.34 no.4
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    • pp.1077-1080
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    • 2013
  • Fluorinated polymaleimides with high thermal stability and low optical absorption loss in the optical communication wavelength of $1.55{\mu}m$ were investigated for application in low-loss waveguide materials. The fluorinated polymaleimides were prepared from two monomers phenylmaleimide (H-PMI) and pentafluorophenylmaleimide (F-PMI). All synthesized copolymers had high thermal stability (decomposition temperature $(T_d)=380-430^{\circ}C$). The refractive index of the copolymers could be tuned from 1.4969 to 1.5950 in the TE mode and from 1.4993 to 1.5932 for the TM mode at 632.8 nm by copolymerizing different weight ratios of H-PMI and F-PMI. The refractive index of the copolymers decreased with increasing F-PMI content. In addition, when the amount of F-PMI was increased, optical loss and absorption loss at 632.8 nm and 1550 nm, respectively, decreased.