• 제목/요약/키워드: photorefractive

검색결과 128건 처리시간 0.019초

Synthesis and Characterization of a New Photoconducting Poly(siloxane) Having Pendant Diphenylhydrazone for Photorefractive Applications

  • Lee, Sang-Ho;Jahng, Woong-Sang;Park, Ki-Hong;Kim, Nakjoong;Joo, Won-Jae;Park, Dong-Hoon
    • Macromolecular Research
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    • 제11권6호
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    • pp.431-436
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    • 2003

  • A new photoconducting polymer, diphenyl hydrazone-substituted polysiloxane, was successfully synthesized by the hydrosilylation method and characterized by FT-IR, $^1$H-NMR, and $^{29}$ Si-NMR spectroscopy. The glass transition temperature (T$_{g}$) of the polysiloxane having pendant diphenyl hydrazone was ca. 62 $^{\circ}C$, which enabled a component of a low-T$_{g}$ photorefractive material to be prepared without the addition of any plasticizers. This polysiloxane, with 1 wt% of $C_{60}$ dopant, showed a high photoconductivity (2.8 ${\times}$ 10$^{-12}$ S/cm at 70 V/${\mu}{\textrm}{m}$) at 633 nm, which is necessary for fast build-up of the space-charge field. A photorefractive composite was prepared by adding a nonlinear optical chromophore, 2-{3-[2-(dibutylamino)-1-ethenyl]-5,5-dimethyl-2-cyclohexenylidene} malononitrile, into the photoconducting polysiloxane together with $C_{60}$ . This composite shows a large orientation birefringence ($\Delta$n = 2.6 ${\times}$ 10$^{-3}$ at 50 V/${\mu}{\textrm}{m}$) and a high diffraction efficiency of 81 % at an electric field of 40 V /${\mu}{\textrm}{m}$.textrm}{m}$.EX>.

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Lithium niobate 단결정의 첨가 이온$(Zn^{2+},;Mg^{2+})$에 따른 광손상 특성에 관한 연구 (On the photorefractive resistance characteristics of lithium niobate single crystals with doping)

  • 김기현;심광보;오근호
    • 한국결정성장학회지
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    • 제8권1호
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    • pp.10-17
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    • 1998

  • Lithium Niobate($LiNbO_3$) 단결정 소재의 광손상에 대한 저항성을 향상시키는 첨가이온으로 잘 알려져 있는 $Mg^{2+}$ 및 $Zn^{2+}$ 이온을 첨가하여 육성한 단결정들의 특성을 비교 분석하였다. 특히 고강도 laser 광의 조사시에 더욱 우수한 특성을 보이는 것으로 알려진 $Zn^{2+}$이온의 첨가량에 따른 광학적 특성 및 전기적 특성의 변화를 측정하여 광손상 저항성을 평가하였으며, 고강도 laser 기기에의 응용 가능성을 고찰하였다.

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$LiNbO_3$:MgO 결정에서 광굴절 격자의 회절 특성 (Diffractive characteristics of the photorefractive gratings in $LiNbO_3$:MgO)

  • 이재철;장지웅;김준태;신승호
    • 한국광학회지
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    • 제10권5호
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    • pp.391-395
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    • 1999

  • 4% 물의 MgO가 도핑된 광굴절 $LiNbO_3$ 결정에 기록된 광굴절 격자의 회절 효율과 응답시간을 측정하였다. 이 실험에는 고출력 펄스 Nd:YAG 레이저(Q-switch mode,$\lambda$=532nm)와 연속 발진 아르곤 이온 레이저($\lambda$=514.5nm)가 사용되었다. 두 종류의 레이저 광속에 대한 실험에서 광학계의 배열을 동일하게 하고 2광파 혼합 조건에서 레이저 광속의 세기를 1.6~100W/$\textrm{cm}^2$까지 변화시켜가며 최대 회절 효율과 기록 및 소거시의 응답시간을 측정하였다. 두 실험에서 얻은 결과를 비교하고 분석 하였다.

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Effect of the Photosensitizer on the Photo refractive Effect Using a Low $T_g$ Sol-Gel Glass

  • Choi, Dong-Hoon;Jun, Woong-Gi;Oh, Kwang-Yong;Yoon, Han-Na;Kim, Jae-Hong
    • Macromolecular Research
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    • 제11권4호
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    • pp.250-255
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    • 2003

  • We prepared the photorefractive sol-gel glass based on organic-inorganic hybrid materials containing a charge transporting molecule, second-order nonlinear optical (NLO) chromophore, photosensitizer, and plasticizer. Carbazole and 2-{ 4-[(2-hydroxy-ethyl)-methyl-amino]-benzylidene}-malononitrile were reacted with isocyanato-triethoxy silane and the functionalized silanes were employed to fabricate the efficient photorefractive media induding 2,4,7-trinitrot1uorenone (TNF) to form a charge transfer complex. The prepared sol-gel glass samples showed a large net gain coefficient and high diffraction efficiency at a certain composition. As the concentration of photosensitizer increased, the photorefractive properties were enhanced due to an increment of charge carrier density. Dynamic behavior of the diffraction efficiency was also investigated with the concentration of the photosensitizer.

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