• Proceedings of the Optical Society of Korea Conference
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• 1998.08a
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• pp.86-87
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• 1998

• Proceedings of the Optical Society of Korea Conference
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• 2007.07a
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• pp.279-280
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• 2007

• Proceedings of the Optical Society of Korea Conference
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• 2007.02a
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• pp.253-254
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• 2007

• Proceedings of the Optical Society of Korea Conference
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• 1996.09a
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• pp.36-36
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• 1996

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.256-257
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• 2005

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.76-77
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.393-394
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• 2008

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.9-11
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• 2002

We improve the free-space optical interconnection efficiency by using circular aperture computer-generated hologram (CGH). In free-space optical interconnection system using CGH, the single CGH is composed of sub-CGHs, which can change the direction of input beams to desired output positions, by Fourier transform. Each sub-CGH is rectangular shape, so the input beams through each sub-CGH are transformed to sinc functions in output plane. The side lobes of each sinc function are superimposed in output plane and they result in detection error in output plane, so the detection efficiency is low. We use the circular shaped sub-CGHs in order to reduce the side lobe value in output plane instead of rectangular shaped sub-CGHs. The each input beam is transformed to first-order Bessel functions through circular shaped sub-CGHs in output plane. The side lobes of first-order Bessel functions us low values compared with side lobes of sinc function, so we can improve the detection efficiency in output plane. We use binary phase modulated CGH, and confirm this improvement results by simulation.

• Journal of the Korean Solar Energy Society
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• v.31 no.1
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• pp.31-36
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• 2011

CF(Circular Fresnel) POF(Plastic Optical Fiber) daylighting system is a beam daylighting system utilizing solar direct beam radiation. In this study, a CF POF daylighting system has been introduced, developed and applied to KIER test buildings. The CF POF daylighting system consists of three parts: light collector, light transmitter and light diffuser. The light collector includes a Circular Fresnel lens focusing solar direct illuminance by sun tracking. The light transmitter contains the POF cable which has light transmission loss of 4.5% per meter. The light diffuser has about 80% diffuser efficiency. This study aims to evaluate of POF daylighting system performance. At the results of a CFPOF system performance evaluation, the theoretical CFPOF system efficiency was 41.9% and the actual CFPOF system efficiency at the KIER test building was 37.5%. The difference was due partly to the connecting efficiency.

• Transactions of Materials Processing
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• v.15 no.1 s.82
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• pp.21-26
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• 2006

A optical head unit for nano optical probe array was developed. The optical probe array is generated by Talbot effect. The shape and thickness of microlens array(MLA) were designed to minimize the spot size at the foci of MLA. To increase the optical efficiency of the system and obtain the large tolerance for fabrication, aperture size was theoretically optimized. Then microlens illuminated aperture array(MLIAA) as an optical head unit was fabricated using a ultra violet(UV) molding process on aluminum aperture array. In this process, Al aperture array was fabricated separately using the photolithography and reactive ion etching(RIE) process. Optical properties of the generated optical probes were measured and compared at Talbot distance from the aperture array having a diameter of $1{\mu}m$ and MLIAA.