• 한국광학회지
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• 제15권4호
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• pp.391-396
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• 2004

인공위성용 지구관측 카메라나 우주관측 망원경에는 크기와 무게의 제약 때문에 Cassegrain 방식의 망원경이 많이 쓰인다. 이와 같은 우주광학계의 성공적인 임무수행을 위해서는 망원경부의 정밀한 광학정렬이 매우 중요하다. 본 논문에서는 정렬 정밀도에 따른 Cassegrain 방식 망원경부의 광학정렬 방법 중, 간섭무늬를 이용한 방법, 파면오차를 이용한 방법, 역최적화 광학정렬 방법 등을 모사를 통해 제시하고, 현재 개발 중인 구경 300 mm급 소형 위성용 카메라에 적용한 광학정렬 실험 결과를 정리한다.

• 한국광학회지
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• 제15권4호
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• pp.313-320
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• 2004

위상편이 회절격자 간섭계와 이진 컴퓨터 형성 홀로그램을 제작하여 널 시스템을 구성하고 비구면형상 측정 시스템을 구축하였다. 제안하는 시스템은 비구면형상에 맞게 제작된 이진 컴퓨터 형상 홀로그램과 가시도가 조정된 위상편이 회절격자간섭계로 이루어져있다. 위상편이 회절격자간섭계는 회절격자의 홈 형상이나 간섭을 일으킬 측정광과 기준광을 바꿈으로써 가시도를 쉽게 조절할 수 있고, 높은 수준의 측정 정확도를 가지는 장점을 가지고 있다. 이진 컴퓨터 형성 홀로그램은 비구면의 정보를 통하여 컴퓨터로 수치모사한 후 전자-빔 리토그래피 장비로 제작할 수 있고, 위상편이 회절격자 간섭계, 비구면과 함께 자동곡률측정 방식으로 설치된다. 간섭계와 홀로그램을 제작한 후 비구면을 측정, 실험을 수행하고 시스템을 평가하였다.

• Journal of the Optical Society of Korea
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• 제5권4호
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• pp.140-145
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• 2001

We present a new method of volumetric interferometer, which is intended to measure the three-dimensional coordinates of a moving object in a simultaneous way with a single optical setup. The method is based on the principles of phase-measuring interferometry with phase shifting. Two diffraction point sources, which are made of the polished ends of single-mode optical fibers are embedded on the object. Two spherical wavefronts emanate from the diffraction point sources and interfere with each other within the measurement volume. One wavefront is phase-shifted by elongating the corresponding fiber using a PZT extender. A CCD array sensor fixed at the stationary measurement station detects the resulting interference field. The measured phases are then related to the three-dimensional location of the object with a set of non-liner equations of Euclidean distance, from which the complete set of three-dimensional spatial coordinates of the object is determined through rigorous numerical computation based upon the least square error minimization.

• Journal of the Optical Society of Korea
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• 제20권1호
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• pp.101-106
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• 2016

A pupil filter is a useful technique for modifying the light intensity distribution near the focus of an optical system to realize depth of field (DOF) extension and superresolution. In this paper, we proposed a new design of the phase only pupil filter by using Zernike polynomials. The effect of design parameters of the new filters on DOF extension and superresolution are discussed, such as defocus Strehl ratio (S.R.), superresolution factor (G) and relative first side lobe intensity (M). In comparison with the other two types of pupil filters, the proposed filter presents its advantages on controlling both the axial and radial light intensity distribution. Finally, defocused imaging simulations are carried out to further demonstrate the effectiveness and superiority of the proposed pupil filter on DOF extension and superresolution in an optical imaging system.

• 한국광학회지
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• 제26권4호
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• pp.217-225
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• 2015

본 논문에서는 이중 색지움 렌즈와 삼중 색지움 렌즈의 종색수차 보정식을 이용하여 가시광선 전대역에서 수차를 보정할 수 있는 유리 조합을 연구하고 수차가 보정된 두 렌즈를 결합하여 산업 현장에서 광범위하게 이용되고 있는 비전검사용 텔레센트릭 렌즈를 설계하였다. 그 결과 매우 넓은 파장대역 380 nm ~ 780 nm에서 파면수차를 $0.057{\lambda}$ 를 갖는 광학적 성능을 확보하였으며, 이는 기존에 시판중인 486.1 nm ~ 656.2 nm에서 수차가 보정된 텔레센트릭 렌즈들보다 우수하다는 것을 볼 수 있었다.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.4-11
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• 2005

In this paper, we propose novel optics design for media inside near-field recording (NFR) using hemispherical solid immersion lens (HMS). To obtain strong advantage of data protection and high data capacity simultaneously, HMS based near field optics using aplanatic position of super hemisphere is designed. In this design, to improve small optical tolerance of this aplanatic position, additional aspheric lens surface is added on top of the HMS and it is combined with zoom optics which composed of two single lenses having low numerical aperture (NA). Also, to compensate chromatic aberration which happens seriously in optics using blue laser diode, diffractive optical element is used. Using zoom optics, additional aspheric lens surface, and diffractive optical element together, wavefront aberration and chromatic aberration are effectively reduced in broad range of cover layer thickness and wavelength variation. In addition, In this paper, effect of gap induced aberration is investigated by analyzing different behavior of each TM and TE wave for designed media inside dual-layer NFR optics.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.154-159
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• 2005

The next generation of optical storage systems requires higher numerical aperture (NA) objective lenses and shorter wavelength laser in order to improve the unit areal density. A blu-ray technology satisfies a miniaturization and a high capacity which are the requirements of the portable device. In this paper, we analyze the optical performance of hybrid micro lens and do active alignment. The hybrid micro lens is manufactured by using a wafer based fabrication technology. Optical components of hybrid micro lens are evaluated. The measurement of the optical power, the spot size and the wavefront error awe performed to evaluate the hybrid micro lens with NA 0.85. Using the measured data, we estimate if the performance of hybrid micro lens corresponds to the designed performance. After the performance of hybrid micro lens is evaluated, the integrated optical pickup and the hybrid micro lens are assembled by active alignment using UV curing and the optical performance of SFFOP is satisfied with BD specifications.

• Journal of the Optical Society of Korea
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• 제19권6호
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• pp.604-613
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• 2015

An unobstructed off-axis two-mirror system is presented in this paper. First a suitable initial configuration is established based on third-order aberration theory. In order to achieve a wide field of view (FOV) with high image quality , the diffractive mirror is adopted in the two-mirror system to increase the optimization freedom and the aberration relationship between diffractive phase coefficients and Zernike coefficients is derived. Furthermore, a complete comparison design example with a focal length of 1200 mm, F-number of 12, and FOV of 40° × 2° is given to verify the aberration correction ability of the diffractive mirror. The system average wavefront error is 0.007 λ (λ=0.6328 μm) developed from 0.061 λ when the system didn’t adopt the diffractive mirror. In this system the phase modulation function of the diffractive mirror is established as an even function of x, so we could obtain a symmetrical imaging quality about the tangential plane, and the symmetric aberration performance also brings considerable convenience to alignment and testing for the system.

• Journal of the Optical Society of Korea
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• 제9권1호
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• pp.26-31
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• 2005

We describe the design and the implementation of video-rate reflection confocal scanning microscopy (CSM) using an acousto-optical deflector (AOD) for the fast horizontal scan and a galvanometer mirror (GM) for the slow vertical scan. Design parameters of the optical system are determined for optimal resolution and contrast. The OSLO simulations show that the performances of CSM are not changed with deflection angle and the wavefront errors of the system are less than 0.012λ. To evaluate the performances of designed CSM, we do a series of tests, measuring lateral and axial resolution, real time image acquisition. Due to a higher axial resolution compared with conventional microscopy, CSM can detect the surface of sub-micrometer features. We detect 138㎚ line shape pattern with a video-rate (30 frm/sec). And 10㎚ axial resolution is archived. The lateral resolution of the topographic images will be further enhanced by differential confocal microscopy (DCM) method and computational algorithms.

• Journal of the Optical Society of Korea
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• 제19권5호
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• pp.521-530
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• 2015

Active optics is a key technology for future large-aperture space telescopes. In the design of deformable mirrors for space applications, the design parameter trade-off between the number of regularly configured actuators and the correction capability is essential but rarely analyzed, due to the lack of design legacy. This paper presents a parametric module method for integrated modeling of deformable mirrors with regularly configured actuators. A full design parameter space is explored to evaluate the correction capability and the mass of deformable mirrors, using an autoconstructed finite-element parametric modeling method that utilizes manual finite-element meshing for complex structures. These results are used to provide design guidelines for deformable mirrors. The integrated modeling method presented here can be used for future applied optics projects.