• 제목/요약/키워드: Bragg's law

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Fabrication and Optical Characterization of Colloidal 3-D Photonic Crystals

  • N. Y. Ha;Y. Woo;Park, Byungchoo;J. W. Wu
    • 한국진공학회지
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    • 제12권S1호
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    • pp.15-16
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    • 2003
  • 3-D photonic band-gap structures are fabricated from dielectric colloidal polystyrene beads through a centrifuge method. The fabricated photonic crystals exhibit opalescent colors under white light and show a clear diffraction peak dependent on the incident angle of the light beam. Also the scanning electron microscope image was taken to verify the face-centered cubic crystal structure. Bragg's law and Snell's law are employed to describe the position of angle resolved diffraction peaks. It was shown that the optically deduced effective refractive index and lattice constants were in good agreement with the crystal structure identified by scanning electron microscope.

포토닉 밴드갭 광결정의 제작과 선형 및 비선형 광학 특성 연구 (Fabrication and Linear & Nonlinear Optical Characterization of Photonic Crystals)

  • Ha Na Yeong;U Yeon Gyeong;Hwang Ji-Su;Jang Hye-Jeong;Park Byeong-Ju;U Jeong-Won
    • 한국광학회:학술대회논문집
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    • 한국광학회 2002년도 하계학술발표회
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    • pp.162-163
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    • 2002
  • 1-D photonic band-gap structure is identified in a cholesteric liquid crystal system. The optical transmission spectrum is measured and compared with the theoretical analysis. Nonlinear transmission is measured near the band edge. Also 3-D photonic band-gap structures are fabricated from dielectric colloidal polystyrene beads through a centrifuge method. The fabricated photonic crystals exhibit opalescent colors under white light and show a clear diffraction peak dependent on the incident angle of the light beam. Also the scanning electron microscope image was taken to verify the face-centered cubic crystal structure. Bragg's law and Snell's law are employed to describe the position of angle resolved diffraction peaks. It was shown that the optically deduced effective refractive index and lattice constants were in good agreement with the crystal structure identified by scanning electron microscope.

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Low-e용 산화물 다층박막 IGZO/Ag/IGZO의 구조적, 광학적 특성 분석 (Structural and Optical Properties of Multilayer Films of IGZO / Ag / IGZO for Low Emissivity Applications)

  • 왕홍래;김홍배;이상렬
    • 한국전기전자재료학회논문지
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    • 제26권4호
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    • pp.321-324
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    • 2013
  • In this study, The RF magnetron sputter and evaporator was on glass substrates 30 mm ${\times}$ 30 mm OMO multilayer thin film structure is applied to the low-e. Structural and optical properties, a thin film was produced, the variable was placed into a variable deposition time of the oxide layer. According to the XRD measurement results there is no peak that satisfies the Bragg's law ($2dsin{\theta}=n{\lambda}$) which confirmed that it is an amorphous structure. RMS value of the results of the AFM measurement, has a roughness of less than 2 nm. transmittance measurements results, visible light region an average 80%, IR region 40% showed.

양면 중첩기법을 이용하는 새로운 광대역의 소형 포토닉 밴드갭 구조 (A Novel Wideband and Compact Photonic Bandgap Structure using Double-Plane Superposition)

  • 김진양;방현국
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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    • pp.413-422
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    • 2002
  • A novel photonic bandgap(PBG) structure is proposed and measured for wide bandgap and compact circuit applications. The proposed structure realizes the ultra-wideband bandgap(2-octave) characteristics by superposing two different PBG structures into a coupled double-plane configuration. A low pass filter fabricated using 3-period of the PBG cells shows 2-octave 10 ㏈ stopband from 4.3 to 16.2 ㎓ and 0.2 ㏈ insertion loss in the passband. Moreover, we confirmed that 44∼70 % size reduction can be achieved using the proposed PBG structures. We expect this novel double-plane PBG structure is widely used for compact and wideband circuit applications, such as compact high-efficiency power amplifiers using harmonic tuning techniques.

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