• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 하계학술발표회
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• pp.200-201
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• 2000

원자와 빛의 결맞음 효과로서 나타나는 많은 흥미로운 현상들 중에서 전자기파 유도 투과(Electro-magnetic Induced Transparency ; EIT)는 원자가 공진주파수를 가진 레이저와 상호작용하였을 때, 광자를 흡수하지 않고 투과하는 현상으로서, 주로 3준위 구도에서 연구되어왔다. 그러나 최근 축퇴된 2준위 구도에서 원자와 빛의 결맞음 효과가 연구되면서 EIT와 정반대의 현상인 전자기 유도 흡수(Electromagnetic Induced Absorption ; EIA)의 관측이 보고되었고 그것과 연관된 물리적 특성들의 연구가 시도되고 있다. (중략)

• 폴리머
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• 제36권4호
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• pp.478-485
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• 2012

Bicyclo(2,2,2)oct-7-ene-2,3,5,6-tetracarboxylic dianhydride(BTDA)와 1,3-bis(3-aminophenoxy)benzene(BAPB) 단량체를 사용하여 중합한 폴리아믹산(poly(amic acid))에 용액 삽입법을 이용해서 다양한 함량의 유기화 점토를 넣은 후 열 이미드화 방법을 통해 투명한 나노복합체 polyimide(PI) 필름을 합성하였다. 0-1.5 wt%의 다양한 함량의 유기화점토를 포함하는 복합체 필름을 제조한 후, 필름의 광 투과성, 모폴로지, 그리고 가스차단성을 각각 측정하였다. 1.0 wt%의 Cloisite 30B가 포함된 복합체에서 가장 우수한 가스차단성이 측정되었으며, 유기화 점토의 함량이 증가하게 되면 가스차단성은 오히려 감소하였다. PI 복합체 필름은 우수한 광 투과성을 가지며 대체로 무색을 나타내었다. 하지만 점토의 함량이 증가함에 따라 광 투과성은 조금씩 감소하였다. Cloisite 30B가 포함된 투명한 PI 복합체 필름의 광 투과성과 가스차단성을 더 자세히 연구하기 위하여 100-140%까지 다양한 비율로 이축연신하였다. 120% 이상 연신된 PI 복합체 필름에서 고분자 매트릭스에 점토가 균일하게 분산되어 박리되었음을 확인 하였으며, 가장 높은 가스 차단성은 130%로 이축연신된 필름에서 확인하였다.

• 한국광학회:학술대회논문집
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• 한국광학회 2003년도 제14회 정기총회 및 03년 동계학술발표회
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• pp.230-231
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• 2003

$KNbO_3$is one of the best materials for efficient nonlinear frequency conversion, due to its large nonlinear optical coefficient ($d_{33}$ ＝ 20.6 pm／V), wide transparency range (0.4 ~ 5 $\mu$m) and freedom from photorefractive effects. Quasi-phase-matched second harmonic generation using periodically poled $KNbO_3$ (PPKN) crystals has been reported. Here we report on fabrication of PPKN and demonstration of a pulsed optical param etric oscillator (QPM OPO) pumped by an Nd：YAG laser. (omitted)

• 열처리공학회지
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• 제25권2호
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• pp.85-89
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• 2012

Transparent conductive ZnO/Ag/ZnO (ZAZ) multilayer films were deposited by Radio frequency (RF) magnetron sputtering and direct current (DC) magnetron sputtering. The effects of post deposition vacuum annealing temperature on the structural, electrical and optical properties of the ZAZ multilayer films were investigated. The thickness of ZAZ films is kept constant at ZnO 50 nm/Ag 5nm/ZnO 45 nm, while the vacuum annealing temperatures were varied from 200 and $400^{\circ}C$, respectively. As-deposited ZAZ films exhibit a sheet resistance of $6.1{\Omega}/{\Box}$ and optical transmittance of 72.7%. By increasing annealing temperature to $200^{\circ}C$, the resistivity decreased to as low as $5.3{\Omega}/{\Box}$ and optical transmittance also increased to as high as 82.1%. Post-deposition annealing of ZAZ multilayer films lead to considerably lower electrical resistivity and higher optical transparency, simultaneously by increased crystallization of the films.

• 수산해양기술연구
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• 제22권2호
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• pp.16-21
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• 1986

Optical properties of sea water were studied in the entrance of Tokyo Bay, Japan. based on the data obtained from seven oceanographic stations in June. 1985. The observation of surface irradiance and underwater irradiance of sea water for eight kind of wavelength (378, 422, 481, 513, 570, 621, 653. 677nm) of sun light was conducted using the underwater irradiameter (Isigawa # SR-8). The mean att;enuation coefficient of the sea water was appeared to be 0.245 (0.042-0.776) and the attenuation co~fficient of the sea water for wavelength appeared such as 0.227 for 378 nm, 0.186 for 422 nm. O. 175 for 481 nm. O. 176 for 513 nm. O. 185 for 570 nm, 0.337 for 621 nm. O. 321 for 653 nm, O. 348 for 677 nm. The transparency was 7.0 m (5.5-9 m). water color was 10 (8.0-13.0) in the study area and the sun altitude was 60.95$^{\circ}$ (43.610-75.500). The relationship between attenuation coefficient (K) and transparency (D) was K = 2.63/ D (1.28/ D- 4. 87/D). The rate of light penetration for eight kind of wave Ie nth (378, 422. 481. 513. 570, 621, 653, 677 nm) were computed with reference to the surface light intensity respectively. The mean rate of light penetration in proportion to depths were 68.63% (46.02-86.07%) in 1 m layer, 18.40% (2.07 -48.48%) in 5m layer, 4.82% (0.042-22.30%) in 10m layer and 1.35% (0.01I-7.42%) in 20m layer. The rate of light penetration at the transparency layer with reference to the surface light intensity was shown as 10.39% (0.77-27.46%).

• 한국재료학회지
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• 제28권10호
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• pp.551-563
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• 2018

Visible and IR windows require a combination of high optical transparency and superior thermal and mechanical properties. Materials, fabrication and characterization of transparent ceramics for visible/IR windows are discussed in this review. The transparent polycrystalline $Y_2O_3$, $Y_2O_3-MgO$ nanocomposites and $MgAl_2O_4$ spinel ceramics are fabricated by advanced ceramic processing and the use of special sintering technologies. Ceramic processing conditions for achieveing fully densified transparent ceramics are strongly dependent on the initial powder characteristics. In addition, appropriate use of sintering technologies, including vacuum sintering, hot-pressing and spark plasama sintering methods, results in outstanding thermal and mechanical properties as well as high optical transparency of the final products. Specifically, the elimination of light scattering factors, including residual pores, second phases and grain boundaries, is a key technique for improving the characteristics of the transparent ceramics. This paper discusses the current research issues related to synthesis methods and sintering processes for yttria-based transparent ceramics and $MgAl_2O_4$ spinel.

• 한국정밀공학회지
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• 제27권9호
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• pp.11-15
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• 2010

In this study, to fabricate a low-resistance and high optical transparency electrode film, the following steps were performed: the design and manufacture of electroforming stamp, the fabrication of a thermal roll-imprinted polycarbonate (PC) patterned films, the filled low-resistance Ag paste using doctor blade process on patterned PC films and spin coating by conductive polymers. As a result of PC films imprinted line width of $26.69{\pm}2\;{\mu}m$, channel length of $247.57{\pm}2\;{\mu}m$, and pattern depth of $7.54{\pm}0.2\;{\mu}m$. Ag paste to fill part of the patterned film with conductive polymer coating and then the following parameters were obtained: a sheet resistance of $11.1\;{\Omega}/sq$ optical transparency values at a wavelength of 550 nm was 80.31 %.

• Macromolecular Research
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• 제16권6호
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• pp.503-509
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• 2008

A series of colorless polyimide (PI) nanocomposite films were synthesized from 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB) with various organoclay contents by solution intercalation polymerization to poly(amic acid)s, followed by thermal imidization. The variation with the organoclay content of the thermomechanical properties, morphology, and optical transparency of the hybrids was examined at organoclay loadings ranging from 0 to 1.0 wt%. The hybrid films showed high optical transparency and almost no color, with cut-off wavelengths ranging from 352 and 356 nm and very low $b^*$ values of 1.19-1.77. The hybrid PI films showed good thermal properties with a glass transition temperature of $280-287^{\circ}C$. Most films did not show any significant thermal decomposition below $490^{\circ}C$. The addition of only a small amount of organoclay was sufficient to improve the tensile properties of the PI films with maximum enhancement being observed at 0.25 wt% organoclay. Moreover, these PI hybrids also had low coefficients of thermal expansion (CTE).

• 공업화학
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• 제21권5호
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• pp.564-569
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• 2010

박막 및 디스플레이 분야에서는 광학 부품소재의 우수한 광 투과성과 투명성을 요구하는 수요가 증가함에 따라 우수한 반사방지 특성의 부여에 대하여 관심이 집중되고 있는 실정이다. 본 연구에서는 반사방지 기능을 부여하기 위하여 졸-겔법에 의한 수열합성법을 통하여 기저 물질 표면에 산화알루미늄을 나노 크기 꽃 형태의 프레임 구조를 가진 단일 산화물층을 형성시키고자 하였다. 코팅 층 시편의 특성은 UV-Vis 분광기, FT-IR 분광기, XRD 및 FE-SEM을 이용하여 분석하였다. 알루미나 졸이 코팅된 시편들의 모폴로지는 수열합성의 온도와 시간 및 초음파 제공에 의해 조절되도록 하였다. 꽃 형태의 나노 프레임 구조 형태로 구성된 코팅 층에서 높은 광투과율과 반사방지특성이 발현되었다.

• 한국통신학회논문지
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• 제24권10B호
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• pp.1832-1840
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• 1999

논문에서는 WDM 기술을 사용하는 완전 광전달망에서 장애를 복구할 수 있는 양 방향 BLSR/4 WDM/SHR 구조의 네트워크를 설계하였다. 제안한 네트워크는 전기적 기능이 없는 완전 광소자를 사용하여 높은 수준의 투명성을 제공하고, BLSR/4 SHR 구조를 사용함으로써 장애 복구를 효율적으로 수행할 수 있다. 또한, 제안한 BLSR/4 WDM/SHR의 여러 장애에 대한 생존성을 분석하기 위한 모델을 제시하였으며, 전파 시간, 처리 시간, 절체 시간의 파라미터를 사용하여 복구 성능을 분석하였다.