• 제목/요약/키워드: photonic band gap

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Fabrication of Polymer Laser Device by Two-Photon Induced Photopolymerization Technique

  • Yokoyama, Shiyoshi;Nakahama, Tatsuo;Miki, Hideki
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.231-231
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    • 2006
  • We fabricated a polymer sub-microstructure for optical device application by two-photon-induced laser lithography technique. Polymer pattern could be minimized as small as ${\sim}100\;nm$. The photopolymerization resin contains laser-dye, thus promising a high level of the optical gain. We utilized the lithography technique to the photonic crystal application, where the template of the two-dimensional photonic crystal was modified by polymer gain medium as defect-shape and line-shape orientations. Photonic band gap effect from polymer-doped photonic crystals is expected to exploit the application such as organic solid-state laser device.

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Fabrication and Optical Characterization of Colloidal 3-D Photonic Crystals

  • N. Y. Ha;Y. Woo;Park, Byungchoo;J. W. Wu
    • Journal of the Korean Vacuum Society
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    • v.12 no.S1
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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.

Improvement of Performance of Thick and High Dielectric Patch Antennas using Photonic Bandgap Structures (포토닉 밴드갭 구조를 이용한 두껍고 유전상수가 높은 패치 안테나의 성능 향상)

  • 기철실;박익모;임한조;한해욱;이정일
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.1
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    • pp.1-6
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    • 2002
  • This paper presents that photonic bandgap structures suppressing the propagation of surface waves can improve the performance of the patch antennas on a thick and high dielectric constant substrate. The forbidden propagation of surface wave due to the photonic bandgap enhances the radiation efficiency and reduces the back radiation drastically.

The reflection characteristic of one-dimensional photonic crystal using by chalcogenide thin films (칼코게나이드 박막을 이용한 일차원 photonic crystal의 반사 특성)

  • Lee, Jung-Tae;Shin, Kyung;Yeo, Cheol-Ho;Ku, Dae-Sung;Kim, Jong-Bin;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.120-123
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    • 2002
  • In this study it had an excellent optical characteristic, it followed in the creation rate and the refractive index regulation to the ease. Chalcogenide produced the $As_{45}Se_{45}Te_{10}$ thin film and the $MgF_{2}$ thin film. It measured thin film plan simulation, and the thin film has a 1 -dimensional photonic band gap. The chalcogenide $As_{45}Se_{45}Te_{10}$ thin film was measured with the fact that it has a high refractive index (2.6~2.9). The $As_{45}Se_{45}Te_{10}$ and $MgF_{2}$ thin film, have a high refractive index and a low refractive index, it used a simulation and planed period 5-pairs structure, the result was from 500nm to 800nm. It will be able to confirm the characteristic which most of the incidence light reflects, the He-Ne (632.8nm) laser was irradiated in the thin film which stabilized the thin film. $As_{45}Se_{45}Te_{10}$ (high refractive index layer: H) and $MgF_{2}$ (low refractive index layer: L) results which plans the thin film with glass/LHLHLLHLHL/air structure, 632.8nm against transmitance, increased a lot. An application possibility with the filter against a specific wave length was confirmed.

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Design of Linearized VCDRO with Novel PBG Ground Plane and Varactor Circuit (새로운 PBG 접지면과 바랙터 회로를 이용한 선형화된 VCDRO의 설계)

  • 강성민;전종환;구경헌
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.5
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    • pp.63-68
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    • 2004
  • This paper presents a design of 12㎓ VCBRO(voltage controlled dielectric resonator oscillator) using a novel PBG(photonic band gap) ground plane and a varactor circuit that enhances the frequency linearity of VCO with different bias to varactors. The PBG structures are used for suppressing the second and third harmonics without any filters. To simulate the accurate resonating frequency, a DR coupled with microstrip lines is analysed by FTM(finite element method) simulation, and the results are transformed into scattering parameters to design the VCO. Some measured results are presented to show the usefulness of the proposed techniques.

Photonic Band Gaps for Surface Plasmon Modes in Dielectric Gratings on a Flat Metal Surface

  • Song, Seok-Ho;Yoon, Jae-Woong;Lee, Gwan-Su;Oh, Cha-Hwan;Kim, Pill-Soo
    • Journal of the Optical Society of Korea
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    • v.6 no.3
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    • pp.76-82
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    • 2002
  • For dielectric gratings on a flat metal surface, photonic band gaps created by Brags scattering of surface plasmon polaritons are observed. The observation result that directly images this gap is compared with that predicted by a numerical model based on a plane wave expansion. Consistency between the experimental and numerical results is also confirmed by comparison with the well-known calculation method of diffraction, the rigorous coupled wave analysis method.

Electro-controllable omni-directional laser emissions from a helical polymeric network composite film

  • Jang, Won-Gun;Park, Byoung-Choo;Kim, Min-A;Kim, Sun-Woong;Kim, Yun-Ki;Choi, Eun-Ha;Seo, Yoon-Ho;Cho, Guang-Sup;Kang, Seung-Oun;Takezoe, Hideo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.883-886
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    • 2008
  • In optical information technology, an electro-controllable Photonic Band Gap (PBG) in a photonic crystal (PC) material is potentially useful for the manipulation of light. Despite a great deal of research on PBGs, the reliable use of electro-active PBG material systems is restricted to only a few cases because of the complex and limiting nature of the structures involved. Here, we propose a PBG system that uses a liquid crystal (LC) polymer composite. The composite is made of nematic LCs (NLCs) embedded in polymeric helical networks of photo-polymerized cholesteric LCs (CLCs). The composite film shows a large field-induced reversible color shift over 150 nm of the reflection band, due to the reorientational undulation of the helical axis, similar to the Helfrich effect.

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A Study on the Photo Reversible One-dimensional Photonic Crystals Composed of TeOx(x=1.42)/SiO2 (TeOx(x=1.42)/SiO2로 구성된 광가변적인 1차원 광자결정 연구)

  • Kong, Heon;Yeo, Jong-Bin;Lee, Hyun-Yong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.2
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    • pp.99-103
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    • 2015
  • One-dimensional photonic crystals (1D PCs) were fabricated by RF sputtering technique on p-Si (100), and fused quartz substrates. The 1D PCs structures consisted of $TeO_x$ (x=1.42), and $SiO_2$ with the difference refractive index. In order to estimate the effect on a defect level within 1D PCs structures, samples were prepared with both normal, and defect mode. The structural and optical properties were confirmed by Scanning electron microscope (SEM), and Ultraviolet visible near-infrared spectrophotometer (UV-VIS-NIR) respectively. In the case of a 1D PC normal mode without defect layer, it had a photonic band gap (PBG) in the near infrared (NIR) region. In the case of a 1D PC defect mode with defect layer, it had a sharp transmission band owing to a defect level, and moved towards the longer wavelength after exposing He-Cd laser with a wavelength of 325 nm.