• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 창립 20주년기념 특별학술발표회
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• pp.131-132
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• 2009

• 한국광학회지
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• 제22권1호
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• pp.30-34
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• 2011

본 연구에서는 현재 대부분 작업자에 의해 수동으로 이루어지고 있는 단색화장치 내 광학 요소간 광학정렬을 높은 반복도와 고속으로 수행할 수 있는 자동화 방안에 대해 논의하고자 한다. 단색 분광기의 시준거울 자동정렬을 위해 CCD센서를 이용한 위상이미지 상관기법을 핵심기술로 사용하였다. 실험결과 약 10초 내에 시준거울을 정밀하게 자동정렬 할 수 있다.

• 천문학회보
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• 제42권1호
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• pp.56.4-57
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• 2017

The Schwarzschild-Chang off-axis telescope is a "linear astigmatism-free" confocal system. The telescope comprises two pieces of aluminum-alloy freeform mirrors that are fabricated with diamond turning machine (DTM) process. We designed optomechanical structures where optical components in the telescope system can be adjustable on a linear stage. Optomechanical deformation caused by the weight of system itself and its temperature variation is analyzed by the finite element analysis (FEA). The results show that the deformation is estimated in the tolerance range. For the optic-axis alignment of telescope system, three-point alignment (TPA) method is chosen. The TPA method uses three parallel lasers and a plane mirror. Point source images were taken from collimated light and field observation. The performance of optical system was tested by point spread function and aberration measurement of the point sources.

• 한국광학회지
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• 제28권4호
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• pp.146-152
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• 2017

우주용 인공위성 카메라를 구성하는 반사경의 정렬은 광학계의 고분해능, 고성능을 얻기 위한 중요한 과정 중 하나이다. 반사경들의 상호정렬에는 큐브미러(cube mirror)가 대신 사용되기 때문에, 각 반사경과 해당 큐브미러 간의 상호위치관계 정보가 우선 필요하다. 따라서 우주용 카메라 반사경들의 정렬을 위해 각 반사경의 정점과 해당 큐브미러의 상대 좌표값을 정확하게 측정해야하며, 본 논문에서는 컴퓨터 제작 홀로그램(computer-generated hologram, CGH)의 정렬용 세그먼트와 광섬유를 이용하는 새로운 측정 시스템을 제안함으로써 우주용 카메라를 구성하는 반사경의 정점을 요구조건 이내로 측정할 수 있었다. 측정 시스템은 광학계 평가용 간섭계, CGH, 광섬유, 반사경으로 구성되어 있으며, 최종적으로 데오도라이트를 이용해 큐브미러를 기준으로 주 반사경의 정점에 위치한 광섬유 끝단의 3차원 상대 좌표값을 $25{\mu}m$ 이하의 정밀도로 측정할 수 있었다.

• 반도체디스플레이기술학회지
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• 제9권1호
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• pp.11-16
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• 2010

Wafer Pre-Alignment is to find the center and the orientation of a wafer and to move the wafer to the desired position and orientation. In this paper, an area camera based pre-aligning method is presented that captures 8 wafer images regularly during 360 degrees rotation. From the images, wafer edge positions are extracted and used to estimate the wafer's center and orientation using least squares circle fitting. These data are utilized for the proper alignment of the wafer. For accurate alignments, camera calibration methods using high order polynomials are used for converting pixel coordinates into real-world coordinates. A complete pre-alignment system was constructed using mechanical and optical components and tested. Experimental results show that alignment of wafer center and orientation can be done with the standard deviation of 0.002 mm and 0.028 degree, respectively.

• 한국통신학회논문지
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• 제31권11A호
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• pp.1053-1058
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• 2006

본 논문은 GE-PON 등 FTTH용 광액세스망 시스템에 사용되는 저가격 광모듈 제작을 위하여, 1.31/1.49um 양방향 구성의 하이브리드집적 PLC칩을 사용한 효율적인 광모듈 패키징 기술을 제안하였다. 수동 광섬유정렬기술과 nonhermetic 플라스틱 패키지 기술을 적용하여 광모듈을 제작하였으며, 광결합효율과 전기-광학적 특성을 측정하였다. 제작된 광모듈의 광결합효율은 광축정렬 허용오차 40um내에서 0.5dB이하의 광결합손실을 나타내었고, -24dBm 이하의 수신감도와 광출력 1.5mW이상, 소광비 10dB이상, tracking error 0.3dB이하의 온도특성이 GE-PON ONU용 광모듈 규격을 만족함을 확인하였다.

• 센서학회지
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• 제28권1호
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• pp.30-35
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• 2019

Inertial measurement units (IMUs) are widely used for wearable motion-capturing systems in the fields of biomechanics and robotics. When the IMUs are combined with optical motion sensors (hereafter, OPTs) for their complementary capabilities, it is necessary to align the coordinate system orientations between the IMU and OPT. In this study, we compare the application of two coordinate transformation-based orientation alignment methods between two coordinate systems. The first method (M1) applies angular velocity coordinate transformation, while the other method (M2) applies gyroscopic angle coordinate transformation. In M1 and M2, the angular velocities and angles, respectively, are acquired during random movement for a least-square algorithm to determine the alignment matrix between the two coordinate systems. The performance of each method is evaluated under various conditions according to the type of motion during measurement, number of data points, amount of noise, and the alignment matrix. The results show that M1 is free from drift errors, while drift errors are present in most cases where M2 is applied. Thus, this study indicates that M1 has a far superior performance than M2 for the alignment of IMU and OPT coordinate systems for motion analysis.

• Journal of the Optical Society of Korea
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• 제14권3호
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• pp.266-276
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• 2010

In the present study, an optical system is proposed for maskless lithography using a digital micromirror device (DMD). The system consists of an illumination optical system, a DMD, and a projection lens system. The illumination optical system, developed for 95% uniformity, is composed of fly's eye lens plates, a 405 nm narrow band pass filter (NBPF), condensing lenses, a field lens and a 250W halogen lamp. The projection lens system, composed of 8 optical elements, is developed for 4 ${\mu}m$ resolution. The proposed system plays a role of an optical engine for PCB and/or FPD maskless lithography. Furthermore, many problems arising from the presence of masks in a conventional lithography system, such as expense and time in fabricating the masks, contamination by masks, disposal of masks, and the alignment of masks, may be solved by the proposed system. The proposed system is verified by lithography experiments which produce a line pattern with the resolution of 4 ${\mu}m$ line width.

• 한국광학회:학술대회논문집
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• 한국광학회 2008년도 하계학술발표회 논문집
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• pp.387-388
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• 2008

• 한국광학회:학술대회논문집
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• 한국광학회 2006년도 하계학술발표회 논문집
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• pp.401-402
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• 2006