• The Optical Journal
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• s.111
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• pp.34-35
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• 2007

1974년 렌즈와 프리즘 가공으로 시작, 현재는 고난이도의 각종 비구면 생산과 대형물 가공업체로 변모한 서울광학산업(주)(대표.이지웅/www.seoulopt.co.kr)이 최근에는 총 소요비용 10억원 이상을 투자하고 4년여의 시간과 공을 들여 직경 4m급의 대형 가공기 개발에 성공했다. 가까운 일본의 경우 이보다 크고 작은 규모의 노광기 몇 대가 있긴 하나 관련 설비 구축 정도는 일본과 비교해 서울광학산업쪽이 월등하다는 평을 받을만큼 기술과 설비투자에 오랜 기간 노력을 경주해왔다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.6
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• pp.1784-1797
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• 1996

The disk/blade assembly of a turbine engine is made in the shape of a dovetail type or a fir-tree type. Since disk fillet regions or contact surfaces undergo high stress comcentration, fatigue cracks frequentrly occur in the disk/blade assembly. Therefore, it is necessary to analyze the stress distributions in the fir-tree type disk/balde assembly and predict the region of fatigue failure. The stress distributions of the disk/blade assembly were investigated by using the photoelastic method and the finite element method. Two dimensional photoelastic techniques were used to investigate the stress distributions of contact surfaces and fillet regions. TH stress distributions were obtained by the shear-difference method and were compared to the finite element results. It was found that maximum tensile stresses were higher in the fillet region thatn in the contact surfaces of the fir-tree models. The finite element results showed good agreement with the experimental results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.992-993
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• 2002

We have fabricated the diffractive optical head(DOH) for optical pick up, which one adaptable to a optical recoding information storage. DOH consists of a focusing grating coupler(FGC) and a solid immersion Jens(SIL). FGC is device that the light converge into a focus by surface lattice. FGC have been studied as a potential application of pick up head for the information storage. In this study, FGC was designed and fabricated to make focus near to possible diffraction limit. We also fabricated recording head combined with SIL. The focus was measured in the range of $1.1{\mu}m$ as near to possible diffraction limit in the FGC having a focusing length of $600{\mu}m$ and a lattice area of 500 * $500{\mu}m$.