• 한국광학회지
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• 제13권1호
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• pp.27-31
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• 2002

본 논문에서는 광자 크리스탈로 구성된 1$\times$4 광 분배기를 설계하여 특성을 Finite-Difference Time-Domain 방법을 사용하여 고찰하였다. Simulation한 결과 bend에서의 4가지 광자 크리스탈 배열 구조와 입사파의 주파수에 따라 투과 특성이 변하는 것을 관찰하였다. 투과 특성이 가장 좋은 bend구조로 1$\times$4광 분배기를 설계하고 특정 주파수를 입사시킨 결과, 입사파의 파워가 4개로 균등히 나누어 짐과 전체 전송 효율이 약 93%임을 관찰하였다.

• Journal of the Optical Society of Korea
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• 제15권4호
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• pp.340-344
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• 2011

Airborne infrared techniques have been used in wild land fire management for decades. This paper describes a kind of infrared scanning system based on a rotating drum with a tilted porthole underside the plane nose. This design increases the stability of the mechanism system, reduces air resistance and protects inner parts. Aberration characteristics of a tilted ellipsoid porthole are analyzed and an effective solution is invented which makes the system achieve $30^{\circ}$ field of regard. The system's ultimate value of modulation transfer function is near the diffraction limit, which indicates that the performance of the rotating optical system meets the imaging requirements.

• 한국광학회지
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• 제12권3호
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• pp.172-176
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• 2001

입력광파면 왜곡에 따른 광학계의 성능을 Strehl 비로 분석하였다. 입력 광파면의 왜곡을 저주파 왜곡과 고주파 왜곡으로 구분하여 결상면에서의 Strehl 비를 구하고 광학계의 저하시키지 않는 입력 광파면 왜곡의 광축상에서의 진폭을 정량적으로 구하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.451-462
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• 2003

At the paper the method of 3D holographic moving image reconstruction is discused. The main idea of this method is based on the substitution of optically created static hologram by equal diffraction array created by acoustical (AO) field which formed by bulk sound waves. Such sound field can be considered as dynamic optical hologram, which is electrically controlled. At the certain moment of time when the whole hologram already formed, the reference optical beam illuminates it, and due to acoustooptical interaction the original optical image is reconstructed. As the acoustically created dynamic optical hologram is electronically controlled, it can be used for moving 3-dimentional scene reconstruction in real time. The architecture of holographic display for moving scene reconstruction is presented at this paper. The calculated variant of such display laboratory model is. given and discussed. The mathematical simulation of step by step images recording and reconstruction is given. The pictures of calculated reconstructed images are presented. The prospects, application areas, shortcomings and main problems are discussed.

• 한국광학회지
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• 제6권1호
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• pp.1-7
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• 1995

열상장비용 줌망원경계통을 설계하였다. 대물경계는 4배로부터 14배까지 배율이 변화할 수 있는 줌광학계통으로 설계하였고 접안경은 초점거리 25mm의 삼중렌즈계통으로 설계하였다. 처음에는 대물경계와 접안경을 구분하여 설계하고 후에 이를 통합하여 무초점계로 설계하였다. 1st order optics에 의해 계통을 확립하고 3rd order optics에 의해 초기설계를 얻었으며 후에 유한광선추적으로 모든 고차수차를 포함하는 ray aberration 또는 angular aberration이 최소가 되도록 최적화 하였다. 최종설계를 회절광학적 MTF를 계산하여 성능을 평가하였다.

• Journal of the Optical Society of Korea
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• 제14권4호
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• pp.424-430
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• 2010

In coherent anti-Stokes Raman scattering (CARS) microscopy reported until now, conventional microscope objectives are used, so that they are limited for introduction into a living body. Gradient-index (GRIN) rod lenses might be a solution for miniaturized microscope objectives for in-vivo CARS microscopy. However, due to the inherent large amount of chromatic aberration, GRIN rod lenses cannot be utilized for this purpose. CARS imaging catheter, composed of miniaturized microscope objective and fiber bundle, can be introduced into a living body for minimally invasive diagnosis. In order to design the catheter, we have to first investigate design requirements. And then, the optical design is processed with design strategies and intensive computing power to achieve the design requirements. We report the miniaturized objective lens system with diffraction-limited performance and completely corrected chromatic aberrations for an in-vivo CARS imaging catheter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.555-557
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• 1995

In near field optics, optical fiber probe is smaller than the wavelength of light. This small probe makes it possible to overcome the diffraction limit due to wave property of light. In conventional optical systems, the image resolution is governed by wavelength. But in NSOM, it is determined by probe tip size and probe shape. Therefore probe tip size and shape are very important points in near field optics. In this paper, we will suggest the new fabrication methods of optical fiber probe and show that the probe tip size is sub-micrometer using SEM.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.163-167
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• 2013

Aluminum doped zinc oxide (AZO) thin films have been prepared on the glass substrates (Corning 1737) by sol-gel dip-coating method employing zinc acetate and aluminum chloride hexahydrate for the transparent conducting oxide (TCO) applications. 1 at% Al was doped to the ZnO thin films. The effects of post-heating temperature on the crystallization, optical and electrical properties of the AZO films have been investigated. Experimental results showed that post-heating temperature affected the microstructure, electrical resistance, and optical transmittance of the AZO films. From the X-ray diffraction analysis, all films have hexagonal wurtzite crystal structure. Optical transmittance spectra of the AZO films exhibited transmittance higher than about 80% within the visible wavelength region and the optical direct band gap ($E_g$) of these films was increased with increasing post-heating temperature. A minimum resistivity of $2.5{\times}10^{-3}{\Omega}cm$ was observed at $650^{\circ}C$.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.302.1-302.1
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• 2014

We report the growth of high quality zinc oxide (ZnO) thin films on amorphous glass substrates and their structural and optical characteristics. For the growth of ZnO films, mechanically exfoliated ultrathin graphite or graphene layers were used as an intermediate layer because ZnO does not have any heteroepitaxial relationship with the amorphous substrates, which significantly improved the crystallinity of the ZnO films. Structural and optical characteristics of the films were investigated using scanning and transmission electron microscopy, x-ray diffraction, and variable temperature photoluminescence spectroscopy. High crystallinity and excellent optical characteristics such as stimulated emission were exhibited from the high quality ZnO films grown on glass substrates.

• 한국표면공학회지
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• 제30권1호
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• pp.63-68
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• 1997

The effects of the post-deposition annealing on the structural optical properties of sputtered $TiO_2$ thin films were studied; annealing was carried out in air up to $1000^{\circ}C$ for different duration. The results of the X-ray diffraction and the raman spectroscopy showed the annealing-condition dependent structural transformation of $TiO_2$ films from the as-deposited amorphous phase to the anatase and rutil phases. The spectroscopic elliposometry was used to investigate the deposition-condition dependence of the as-deposted films optical constants and also the evolution of the optical constants correlated with the annealing-induced structural transformation.