• 한국안광학회지
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• 제9권1호
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• pp.117-124
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• 2004

본 논문에서는 한국인 안구의 영상자료를 가지고 실안에 유사한 광학적 성능을 갖는 모형안을 설계하였다. 설계 시 활용된 한국인 안구의 임상자료로는 기존에 조사 되어진 젊은 사랑의 정시안 임상자료를 가지고, 그 평균값을 구하여 기초 설계 제원으로 삼았다. 설계 목표로는 구연수차와 비점수차가 실안과 유사한 성능을 갖도록 설정하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.992-997
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• 2003

Aspherical lens design method named ray reverse tracing method is introduced. Differently from the traditional design method, the ray reverse tracing method traces the shape and location of a real object by use of its virtual image. From the result, it was convinced that spherical aberration free aspherical lens could be designed by use of the ray reverse tracing method. Furthermore, it could reduce the degree of dependence of optical characteristics on designer's ability, because deformation terms and optimization can be eliminated, which has been performed in conventional lens design process.

• Journal of the Optical Society of Korea
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• 제13권2호
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• pp.184-192
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• 2009

There are total eight degrees of freedom in designing a three-mirror system. If we correct four kinds of third order aberrations and the system should have the specified effective focal length, the remaining three degrees of freedom can be used for selecting a suitable configuration for a specific application. We suggest an analytic design procedure for a three-mirror telescope system which has a suitably sized secondary mirror and proper separations between mirrors, and is corrected for four kinds of third order aberrations, spherical aberration, coma, astigmatism, and field curvature. Two design examples are shown. One has a compact configuration with off-axial field, the other has relatively long configuration with annular ring field.

• 정보저장시스템학회논문집
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• 제1권1호
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• pp.42-47
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• 2005

We developed an optical pickup system which is used fer Blu-ray Disc. A liquid crystal element was used to make compensation for spherical aberration. Spherical aberration is a difficult problem in the optical pickup system for Blu-ray Disc. To reduce the effects of wavelength variation from the laser source, we designed a diffraction optical element. We took a measurement of all of the parts used to make a pickup system and validated the performance of each part. Then, we made a performance test fur the optical pickup system which we developed for Blu-ray Disc and the results were satisfactory.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.151-152
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• 2005

Blu-ray 디스크에서는 NA=0.85 의 높은 개구수를 채용함으로써 디스크 보호층의 두께 변동에 따른 구면수차 발생량이 매우 커지는 문제가 발생하게 된다. 따라서 디스크 두께 공차 $3{\mu}m$에서 Blu-ray 시스템의 수차 발생 허용수준을 초과한다. 그리고 Multi-layer 디스크의 경우 각 층의 간격이 $25{\mu}m$ 정도의 간격을 두고 배치되어 있어 기록층 사이에서 발생하는 구면수차의 보정이 필요하며, 종래의 기술은 보상범위가 $3{\mu}m$로 한정되어 사용이 불가능하며 또한 대물렌즈 조립공차가 엄격히 관리되어야 하는 문제점을 안고 있었다. 본 연구에서는 액정렌즈에 의한 구면수차 보정으로 이러한 문제점들을 해결하고자 하였다. 액정렌즈는 오목렌즈 액정소자와 볼록렌즈 액정소자로 구성되며 픽업 광학계 내에 조합하여 설계함으로써 Multi-layer 디스크의 두께 변동에 따라 발생하는 구면수차를 보정하고 대물렌즈 조립공차 문제를 해결할 수 있다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.197-202
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• 2005

An aspheric lens is one of a key point optical element in the optical industry. The feature of an aspheric lens is not to have the spherical aberration. An aspheric lens is also essential element for high-precision and light-weight in the optical machine. Generally it have been used in a tailor progression an aspheric lens modelling much. In this study we applied a lay back-tracer using a index of refraction to draw a creative aspheric lens. Also we developed the automatic design program for aspheric lens. We manufactured the aspheric lens and executed a comparison experiment for refraction situation of shape and straightness experiment to inspect the drawn aspheric lens in this study.

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 2004년도 제35차 춘계학술대회
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• pp.69-73
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• 2004

• 한국광학회지
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• 제26권6호
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• pp.299-305
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• 2015

사람 눈의 각막에 평행하게 입사하는 광선의 높이에 따른 결상점을 근사 없이 스넬의 법칙으로 분석하였다. 광선들이 망막의 동일한 한 점에 결상하도록 각막에 입사하는 광선들의 높이에 따른 입사각을 계산하기 위하여 결상점으로부터 광선을 역추적하여 각막 전면에 입사하는 광선의 입사각을 계산 하였다. 눈 자체로는 구면수차를 유발할 수밖에 없기 때문에, 구면 수차를 보정할 수 있는 비구면 렌즈 설계에 대한 조건을 유도 하였다. 계산을 쉽게 하기 위하여 렌즈 후면은 구면으로 고정하고 렌즈 전면을 비구면 렌즈 설계를 위하여 높이에 따른 곡률을 계산하였다.

• Applied Microscopy
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• 제45권1호
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• pp.1-8
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• 2015

We have developed a new HD-2700 (Hitachi High-Technologies Corp., Japan) scanning transmission electron microscope (STEM) that includes an automatic aberration correction function, and a large-solid-angle energy-dispersive X-ray spectroscopy detector that enables high-resolution and sensitive analysis. For observation with atomic resolution, using spherical-aberration-corrected STEM, in order that satisfactory performance of the device can be achieved readily, and within a short time, irrespective of the operator's skill level, a spherical-aberration-correction device with an automatic aberration-correction function was developed. This automatic aberration-correction function carries out the entire correction-related process (aberration measurement, selection and correction) automatically, with automatic selection of the aberrations that require correction, and automatic measurement of the appropriate corrections.

• Journal of the Optical Society of Korea
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• 제19권4호
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• pp.403-408
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• 2015

To evaluate the effects of spherical aberration (SA) correction on optical quality in pseudophakic eyes, we simulated the optical quality of the human eye by computation of the modulation transfer function (MTF). We reviewed the medical records of patients who underwent cataract surgery in Asan Medical Center, retrospectively. A Zywave aberrometer was used to measure optical aberrations at 1-12 postoperative months in patients with AR40e intraocular lens implants. The MTF was calculated for a 5 mm pupil from measured wavefront aberrations. The area under the MTF curve (aMTF) was analyzed and the maximal aMTF was calculated while changing the SA ($-0.2{\sim}+0.2{\mu}m$) and the defocus (-2.0 ~ +2.0 D). Sixty-four eyes in 51 patients were examined. The maximal aMTF was $6.61{\pm}2.16$ at a defocus of $-0.25{\pm}0.66D$ with innate SA, and $7.64{\pm}2.63$ at a defocus of $0.08{\pm}0.53D$ when the SA was 0 (full correction of SA). With full SA correction, the aMTF increased in 47 eyes (73.4%; Group 1) and decreased in 17 eyes (26.6%; Group 2). There were statistically significant differences in Z(3, -1) (vertical coma; P = 0.01) and Z(4, 4) (tetrafoil; P = 0.04) between the groups. The maximal aMTF was obtained at an SA of $+0.01{\mu}m$ in Group 1 and an SA of $+0.13{\mu}m$ in Group 2. Optical quality can be improved by full correction of SA in most pseudophakic eyes. However, residual SA might provide benefits in eyes with significant radially asymmetric aberrations.