• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.208.1-208
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• 2000

• Journal of the Korean Society for Precision Engineering
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• v.28 no.8
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• pp.929-935
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• 2011

As a deterministic finishing process for the optical parts having complex surface, machining performance of the magnetorheological(MR) fluid jet polishing of optical glass are studied and compared with a general water jet polishing. First, design of the jet polishing system which has the special electromagnet-nozzle unit for stabilizing the slurry jet based on MR fluid and the change of jet shape as magnetic field is applied are explained. Second, for the BK7 glass, machining spot and its cross section profile are analyzed and the unique effect of MR fluid jet polishing is shown. Third, both material removal depth and surface roughness are explored in order to investigate the polishing performance of MR fluid jet. With the same ceria abrasives and amount in the polishing slurries, MR fluid jet shows superior machining performance compared to water jet and the difference of material removal mechanism and its resulting performance are described.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.2
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• pp.275-281
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• 2010

This research's goal is to process directly aspherics with big sagment and thin center thickness. If we can process directly aspherics with big sagment and thin center thickness, we think it greatly helps to reduce the time of developing optical system. We made very thin glass using diamond grinding whetstone regarding the trace of tool and the detailed drawing of tool super precisive aspherics that has 0.46mm center thickness and over $30^{\circ}$ segment, $0.1{\mu}m$ machining accuracy, 15nm surface accuracy. We think this research's result will be effective to open new market because it is applied not only cell phone optical system but also CCTV robot optical system, internet phone optical system. Also we expect to enhance the super strong brittle precisive process's possibility with super precisive processing technique that achieves 0.46mm glass center thickness as first in the world.

• Journal of the Semiconductor & Display Technology
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• v.18 no.3
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• pp.12-18
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• 2019

The protective double layer polymer coatings on silica optical fibers are realized by wet-on-wet liquid coating process and they play an important role in final quality of mass produced optical fibers. This numerical study aims to analyze the effects of secondary coating die design parameters by employing two dimensional axisymmetric model of coating cup and coating die geometry and computational fluid dynamics simulations which include temperature dependent viscosity of polymer coating liquids and viscous dissipation heating. Under high speed fiber drawing conditions and pressurized coating liquid supply, the effects of converging die angle are investigated in order to appreciate the change of coating liquid flow patterns such as flow recirculation zone near coating die as well as primary and secondary coating layer thicknesses. The auxiliary coating die to converging coating die is also tested and the results find that this concept is advantageous in achieving stable double layer coatings on silica glass fiber.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.426.1-426.1
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• 2014

For high performance thin film solar cells, texturing surface, enhancing the optical absorptionpath, is pretty important. Textured ZnO:Al transparent oxide layer of high haze is commonly used in Si thin film solar cells. In this paper, novel deposition method for aluminum doped zinc oxide (ZnO:Al) on glass substrates is presented to improve the haze property. The broccoli structure of ZnO:Al layer was formed on chemically etched glass substrates, which showed high haze value on a wide wavelength range.The etching condition of the glass substrates can change not only the haze values of the ZnO:Al of in-situ growth but alsothe electrical and optical properties of the deposited ZnO:Al films.The etching mechanism of the glass substrate affecting on the surface morphology of the glass will be discussed, which resulted in variation of texture of ZnO:Al layer. The optical properties of substrate morphology were also analyzed with EDS and FTIR results. As a result, the high haze value of 85.4% was obtained in the wavelength range of 300 nm to 1100 nm. Furthermore, low sheet resistance of about 5~18 ohm/sq was achieved for different surface morphologies of the ZnO:Al films.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.3
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• pp.124-131
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• 2007

Aspheric glass lenses was fabricated by glass molding press(GMP), which is a plano-aspheric convox shape and intended for use as an optical design of 3 megapixel and 2.5 magnifications zoom in a camera phone module. Transcription ratio of form accuracy (PV) as well as resolution properties was measured for evaluation the molded lens. Form accuracy (PV) of the mold surface was $0.127\;{\mu}m$ in an aspheric and $0.168\;{\mu}m$ in a plano, in case of the molded lens it shows $0.205\;{\mu}m$ and $0.223\;{\mu}m$, respectively. Resolution of the molded lens was measured as a MTF[Contrast]. The molded lens shows contrast of 32.9% at 80 1p/mm and the value is similar with contrast of 33% obtained simulation.

• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.1
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• pp.47-58
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• 2000

Transmittances of SiO2 and ZrO2 thin films, made by the electron beam evaporation method, were measured with a spectrophotometer to be used in determining their optical constants and thicknesses in the envelop method. New color glass lenses with high transmittance, which now can be manufactured in the industry, was successfully designed by using these constants. Also the vacuum evaporator could be mechanically corrected with these constants as correction factors.

• Journal of Information Display
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• v.3 no.4
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• pp.4-7
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• 2002

A recently developed phase separated composite film method has been employed to fabricate a liquid crystal (LC) based electro-optical device using a single glass substrate. The resulting device is made of adjacent parallel layers of LC and polymer maded by phase separation. The LC layer is confined between the solidified polymer layer on one side and the glass substrate on the other. The electro-optical properties of these devices demonstrate their technological potential in light weight and hand-held electronic products.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.262-263
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• 2000

이온교환방법은 착색된 유리를 생산하기 위하여 수세기 전부터 연구되어 왔다. 1972년 Izawa와 Nagome가 silicate 유리에 Tl$^{+}$이온을 치환하여 평판 도파로를 만든 후, 이온교환은 도파로나 마이크로 렌즈제작 등에 활발하게 연구되어 왔다. 유리 도파로는 광의 진행손실이 적으며, 광섬유와의 우수한 호환성, 그리고, 제작이 용이하고 가격이 싼 장점 등으로 인하여 많은 연구가 진행되고 있는 재료이다. 그러나, 유리에 이온교환으로 광소자를 만들기 위해서는 굴절률변화를 정확하게 예측해야한다. 따라서, 유리에서 이온들의 확산특성을 정확하게 분석하고 실험적으로 확립하는 연구는 매우 중요하다고 하겠다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.425-426
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• 2006