• 한국광학회:학술대회논문집
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• 한국광학회 1997년도 Advance Program of 14th optics andquantum Electronics conference, 1997제14 회 광학 및 양자전자 학술 발표회 논문 요약집
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• pp.100-100
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• 1997

• 한국광학회:학술대회논문집
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• 한국광학회 2002년도 제13회 정기총회 및 2002년도 동계학술발표회
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• pp.138-139
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• 2002

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.139.2-139.2
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• 2016

Electrons and phonons in chalcogenide-based materials play are important factors in the performance of an optical data storage media and thermoelectric devices. However, the fundamental kinetics of carriers in chalcogenide materials remains controversial, and active debate continues over the mechanism responsible for carrier relaxation. In this study, we investigated ultrafast carrier dynamics in an multilayered $\{Sb(3{\AA})/Te(9{\AA})\}n$ thin film during the transition from the amorphous to the crystalline phase using optical pump terahertz probe spectroscopy (OPTP), which permits the relationship between structural phase transition and optical property transitions to be examined. Using THz-TDS, we demonstrated that optical conductance and carrier concentration change as a function of annealing temperature with a contact-free optical technique. Moreover, we observed that the topological surface state (TSS) affects the degree of enhancement of carrier lifetime, which is closely related to the degree of spin-orbit coupling (SOC). The combination of an optical technique and a proposed carrier relaxation mechanism provides a powerful tool for monitoring TSS and SOC. Consequently, the response of the amorphous phase is dominated by an electron-phonon coupling effect, while that of the crystalline structure is controlled by a Dirac surface state and SOC effects. These results are important for understanding the fundamental physics of phase change materials and for optimizing and designing materials with better performance in optoelectronic devices.

• 한국실내디자인학회논문집
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• 제24권3호
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• pp.68-78
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• 2015

Nendo, which was established in Tokyo in 2002, is a design company established by Oki Sato, which is gaining reputation as a new design group representing Japan through numerous design tasks encompassing diverse design sectors, such as architecture, interior, furniture, graphic, and products. This study was conducted to investigate the formative features of Nendo furniture by reviewing 133 pieces of Nendo furniture designed for the last ten years and identify the general characteristics of Nendo furniture by reviewing the time of launch, product launch type, and furniture type. As a result, the design features of Nendo furniture are as follows: First, the shapes of basic materials including boards, lumber, and bars are maintained intact and Nendo furniture has simple and moderate design without complicated or decorative elements. Second, Nendo furniture has simply embodied a design characterized by simple transformation, minimization of furniture elements, and rearrangement. Third, Nendo presents new and simple furniture differentiated from other pieces of furniture using optical illusions. Such expressions of optical illusions which are hardly found in preexisting furniture are a major feature of Nendo furniture. Fourth, a majority of chairs of Nendo cause optical illusions with the minimized size. In addition, their top boards made of transparent glass and mirror cause optical illusions with the properties of materials. In short, design of Nendo furniture is characterized by formative expressions, expressions of optical illusions, and differentiated use of materials. Fifth, Nendo keeps launching new furniture items in various exhibitions. As a result, Nendo makes furniture with its own unique characteristics based on its diverse studies and experiments which are applied to furniture design in a realistic way. In summary, design of Nendo furniture is characterized by simply embodied design based on small differences in daily life, minimalism with simple and moderate shapes, and its own witty uniqueness based on formative expressions, expressions of optical illusions, and use of materials differentiated from other furniture brands.

• 폴리머
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• 제30권2호
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• pp.158-161
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• 2006

본 연구에서는 고온 고압하의 반응기내에서 일차 아민(primary amine)과 PMMA의 이미드화 반응을 유도하여 내열성 플라스틱 광섬유(plastic optical fiber, POF) 재료인 polyglutarimide(PGI)를 제조하였다. 에틸 아민과 이소프로필 아민, 두 종류를 사용하였으며, 반응시 함량을 다르게 하여 합성한 후 PGI의 여러 가지 물성을 비교하였다. $^1H$ NMR과 FTIR을 사용하여 PGI의 이미드 전환율을 비교하였고, DSC와 TGA를 통해 열적 특성을 조사하였다. 에틸 아민을 사용하여 합성된 PGI 화합물들이 높은 이미드 전환율을 보이면서 향상된 내열성을 나타내었다. POF재료로서 필수적인 광학적 성질은 분광광도계와 아베굴절계로 굴절률과 광 투과율을 조사하였다. 대부분의 PGI는 PMMA 수준의 광 투과율을 유지하였으며, 보다 높은 굴절률을 나타내었다. 이것은 합성된 PGI가 POF 코어물질로써 우수한 광 효율 및 내열성 향상에 기여할 수 있음을 의미한다.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1205-1211
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• 2013

The structural and optical properties of the ZnO, Al-doped ZnO, Ga-doped ZnO, and In-doped ZnO nanorods were investigated using field-emission scanning electron microscopy, X-ray diffraction, photoluminescence (PL) and ultraviolet-visible spectroscopy. All the nanorods grew with good alignment on the ZnO seed layers and the ZnO nanorod dimensions could be controlled by the addition of the various dopants. For instance, the diameter of the nanorods decreased with increasing atomic number of the dopants. The ratio between the near-band-edge emission (NBE) and the deep-level emission (DLE) intensities ($I_{NBE}/I_{DLE}$) obtained by PL gradually decreased because the DLE intensity from the nanorods gradually increased with increase in the atomic number of the dopants. We found that the dopants affected the structural and optical properties of the ZnO nanorods including their dimensions, lattice constants, residual stresses, bond lengths, PL properties, transmittance values, optical band gaps, and Urbach energies.

• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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• pp.68-68
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• 2000

In this paper a very brief review of historical development of optical science and technology in China is presented. More attention has been pain on Modem Optics, which developed since 1950s. The recent development of optical science and technology in following fields are introduced. 1. Optical engineering and instrumentation (tracking theodolites, high speed cameras, satellite laser ranging systems, satellite flying attitude control, cameras for remote sensing, astronomical optical instrument) 2. Applied optics (adaptive optics, optical metrology, infrared optics, optical processing, optical holography) 3. Laser science and technology (ultrashort pulse lasers, UV-X ray lasers, high power laser facilities and laser fusion, laser isotope separation) 4. Laser and nonlinear materials (rare earth elements doped laser glasses and crystals, tunable laser crystals, borate series and organic nonlinear crystals) 5. Optoelectronic science and technology (Optical communication, optical data storage, optical computing) The current situation and developing prospect of optical and optoelectronic industry in China are presented. Furthermore it points out that the optical industry could be developed vigorously only if products development capacity is enhanced and new products industrialization is heightened. The main research and education institutions in the optics field in China, as well as the Chinese Optical Society (COS) are introduced.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2000년도 제1회 신소재 심포지엄(차세대 광소재 심포지엄)
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• pp.13-35
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• 2000

• 한국재료학회지
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• 제23권8호
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• pp.469-475
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• 2013

Al-doped ZnO(AZO) thin films were synthesized using atomid layer deposition(ALD), which acurately controlled the uniform film thickness of the AZO thin films. To investigate the electrical and optical properites of the AZO thin films, AZO films using ALD was controlled to be three different thicknesses (50 nm, 100 nm, and 150 nm). The structural, chemical, electrical, and optical properties of the AZO thin films were analyzed by X-ray diffraction, X-ray photoelectron spectroscopy, field-emssion scanning electron microscopy, atomic force microscopy, Hall measurement system, and UV-Vis spectrophotometry. As the thickness of the AZO thin films increased, the crystallinity of the AZO thin films gradually increased, and the surface morphology of the AZO thin films were transformed from a porous structure to a dense structure. The average surface roughnesses of the samples using atomic force microscopy were ~3.01 nm, ~2.89 nm, and ~2.44 nm, respectively. As the thickness of the AZO filmsincreased, the surface roughness decreased gradually. These results affect the electrical and optical properties of AZO thin films. Therefore, the thickest AZO thin films with 150 nm exhibited excellent resistivity (${\sim}7.00{\times}10^{-4}{\Omega}{\cdot}cm$), high transmittance (~83.2 %), and the best FOM ($5.71{\times}10^{-3}{\Omega}^{-1}$). AZO thin films fabricated using ALD may be used as a promising cadidate of TCO materials for optoelectronic applications.

• 열처리공학회지
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• 제26권6호
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• pp.288-292
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• 2013

We have considered the influence of electron irradiation energy of 300, 600 and 900 eV on the stuctural, electrical and optical properties of GZO/$TiO_2$ thin films prepared with RF magentron sputtering. The optical transmittance and electrical resistivity of the films were dependent on the electron's irradiation energy. The electron irradiated GZO/$TiO_2$ films at 900 eV are grown as a hexagonal wurtzite phase and the resistivity is decreased with electron irradiation energy. The GZO/$TiO_2$ films irradiated at 900 eV shows the lowest resistivity of $4.3{\times}10^{-3}{\Omega}cm$. The optical transmittance in a visible wave length region also increased with the electron irradiation energy. The film that electron irradiated at 900 eV shows 82% of optical transmittance and higher work function of 5.18 eV in this study.