• Proceedings of the Optical Society of Korea Conference
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• 1995.06a
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• pp.68-74
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• 1995

한국전자통신연구소에서 개발된 바 있는 KrF 엑시머 레이저 스탭퍼의 개발 과정과 그 결과를 보이고, 동시에 현재 개발중인 ArF 엑시머 레이저 스텝퍼의 진행상황을 보고한다. 본 논문에서는 스탭퍼의 주요 구성요소인 조명계, 투영광학계, 웨이퍼 자동초점 및 자동정렬 시스템을 중심으로 설명하여, KrF와 ArF 에시머 레이저 스탭퍼간의 차이점과 그 특성들을 상호 비교한다.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.90-91
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• 2000

2차 비선형 현상인 제2고조파(Second Harmonic Generation:SHG)는 electric dipole approximation에 의하면 중심대칭성이 있는 물질에서는 발생하지 않는다. 그러나 표면에 대해서는 그 중심대칭성이 깨져 제2고조파가 발생할 수 있게 된다. 즉 bulk에서는 제2고조파가 나오지 않는 반면, 표면에서는 나오게 된다. 본 연구에서는 electric dipole approximation 이상(예를 들면 magnetic dipole, electric quadrupole)을 고려해 시료의 물리적인 성질을 실제 물질계에 가깝게 기술하고자 했다. (중략)

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.4
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• pp.409-415
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• 2011

Purpose: To design applied anamorphic lens that focal length ratio is 3:1 optical system to improve detecting distance. Methods: We defined a boundary condition as $50^{\circ}{\sim}60^{\circ}$ for viewing angle, horizontal direction 36mm, vertical direction 12 mm for focal length, f-number 4, $15{\mu}m{\times}15{\mu}m$ for pixel size and limit resolution 25% in 33l p/mm. Si, ZnS and ZnSe as a materials were used and 4.8 ${\mu}m$, 4.2 ${\mu}m$, 3.7 ${\mu}m$ as a wavelength were set. optical performance with detection distance, narcissus and athermalization in designed camera were analyzed. Results: F-number 4, y direction 12 mm and x direction 36 mm for focal length of the thermal optical system were satisfied. Total length of the system was 76 mm so that an overall volume of the system was reduced. Astigmatism and spherical aberration was within ${\pm}$0.10 which was less than 2 pixel size. Distortion was within 10% so there was no matter to use as a thermal optical camera. MTF performance for the system was over 25% from 33l p/mm to full field so it was satisfied with the boundary condition. Designed optical system was able to detect up to 2.9 km and reduce a diffused image by decreasing a narcissus value from all surfaces except the 4th surface. From sensitivity analysis, MTF resolution was increased on changing temperature with the 5th lens which was assumed as compensation. Conclusions: Designed optical system which used anamorphic lens was satisfied with boundary condition. an increasing resolution with temperature, longer detecting distance and decreasing of narcissus were verified.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.55-60
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• 2002

In this paper, we investigate the MTF in image plane using the shifted magnitude, the shifted direction, and the astigmatism as the real amplitude distribution of incident beam in an optical system is shifted. The shifted magnitudes of incident beam are 0.0, 0.25, 0.5 and 0.75 and the shifted directions of incident beam are 0 and ${\pi}/2$. We also consider the optical system having the astigmatism which are $0.0{\lambda}$, $0.25{\lambda}$, $0.5{\lambda}$, and $0.75{\lambda}$. As the shifted magnitude of the real amplitude distribution of incident beam increases, the MTFs of sagittal and tangential direction in an optical system having an aberration free decrease, but that in an optical system having the astigmatism which is $0.75{\lambda}$ and the shifted direction of incident beam which is ${\pi}/2$ increases. We know from these results that the shift of the real amplitude distribution of the incident beam in an optical system compensates the effect of astigmatism as the shifted direction of that in an optical system is ${\pi}/2$, and Stiles-Crawford effect having the shifted real amplitude distribution of incident beam in pupil area is minimized the effect of astigmatism for eye.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.417-428
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• 2004

We have investigated the optical property of the KAO(Korea Astronomy Observatory) wide field telescope (named NEOPAT-3; Near Earth Object and Satellite Patrol-3) and aligned optical system. The NEOPAT-3 is restricted to V,R,I-filters because of the refractive property of the correcting lens system. Because of the fast focal ratio, the optical performance of the NEOPAT-3 is very sensitive to its alignment factors of the optical system. To make the spot radius smaller than $8{\mu}m$ in rms over 2degree${\times}2$degree field, the optical system must satisfy the following conditions: 1) The tilt error between detector plane and focal plane should be less than 0.05degree. 2) The decenter error between the primary mirror and the correcting lens system should be less than 1mm. 3) The distance error between the primary mirror and the correcting lens system should be less than 2.3mm. In order to align the optical system accurately, we measured the aberrations of the telescope quantitatively by means of curvature sensing technique. NEOPAT-3 is installed temporary on the roof of the TRAO(Taeduk Radio Astronomy Observatory) main building to normalize system performance and to develop automatic observation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.5
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• pp.435-442
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• 2017

A catadioptric optical system produces images by refraction and reflection. To improve the image quality, the shape of the secondary mirror supporters should be determined to ensure that the centering error and tilt of secondary mirror are very small, and the main mirror receives the maximum amount of light. Furthermore, random acceleration vibration has a severe effect on the optical system for observation reconnaissance. In order to obtain the best design under these circumstances, the volume of the secondary mirror supporter must be minimized while satisfying the constraints expressed in standard deviations of the centering error and tilt. It is difficult to analytically calculate the design sensitivities of the standard deviations, because they are statistically defined. Hence, after their second-order regression equations were determined using a response surface methodology, an optimal geometric design was obtained. As a result, it was found that the method proposed in this paper, which included a random vibration analysis, was effective in obtaining the optimal design for a secondary mirror supporter with robustness.

• Korean Journal of Optics and Photonics
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• v.16 no.5
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• pp.440-445
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• 2005

The limitation of measurement accuracy and reliability of autostigmatic null lens system are studied for the cases of using inter-distance of null lenses as the adjustment factor of alignment and fixing the distance by mounting. If we investigate the first case, the wavefront aberration of null lens system is compensated by the adjustment process even though the shape of aspherical surface is not properly fabricated. As the result, it brings about the problem of measurement reliability. However, for the fixing process by mounting null lenses, it doesn't cause the reliability problem because the wavefront aberration of null lens system is not compensated. Further, the fixing process shows nearly same result in measurement accuracy to the adjustment process, that is, $0.0316{\lambda}$ vs. $0.0326{\lambda}$. So, we can conclude the setup for autostigmatic null lens system must be constituted by means of the fixing process. Meanwhile, we introduce and define the alignment aperture on aspheircal mirror, which can be approximated as spherical zone for alignment of null lens system, and besides, we calculate the required fabrication accuracy of the zone for the necessary measurement accuracy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.629-630
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• 2012

• The Optical Journal
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• s.118
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• pp.25-27
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• 2008

국광학거울을 제작하기 위해서는 가공기술과 초정밀 측정기술이 수반되어야 한다. 국내에서는 100개 이상의 광학렌즈 및 거울 가공업체가 있으나 대부분 직경 1인치 이내의 소형광학계를 주로 생산하고 있고 면 형태 역시 구면이 대부분이다. 최근 휴대폰 카메라 등에 비구면을 사용하고 있지만 대부분 다이아몬드터닝 머신 등을 이용한 정밀급 가공수준이므로 대형 광학거울에 같은 기술을 적용할 수 있다고 보기에는 무리가 따른다. 본 원고에서는 대구경 정밀 광학거울 가공, 평가 및 코팅기술을 설명하고 관련 기술의 전망에 관하여 간단히 언급하고자 한다.

• The Optical Journal
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• s.125
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• pp.50-51
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• 2010

인하대학교 광기술교육센터(소장 황보 창권)와 한국광학기기협회(회장 박상진)가 주최하고 지식경제부 등이 후원하는 제7회 산학연 워크숍이 지난 12월 22일 인하대학교 광기술교육장에서 열렸다. '한국광학의 미래'라는 주제로 열린 이번 워크숍에서는 광학의 각 계 분야의 전문가 7명을 초청하여 최근의 광학산업의 흐름과 최신 기술동향에 대해 짚어보고 아래 시장을 전망해 보는 시간이 마련되었다.