• Proceedings of the Korean Vacuum Society Conference
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• 2005.02a
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• pp.39-39
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• 2005

• Proceedings of the Korean Ceranic Society Conference
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• 2004.04b
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• pp.34.3-34.3
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• 2004

• ETRI Journal
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• v.25 no.3
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• pp.149-155
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• 2003

A self-pulsating multisection distributed-feedback laser diode (DFB LD) can potentially realize all-optical clock extraction. This device generally consists of three sections, two DFB sections and one waveguide section. The most important variable in this device is detuning, which is the relative spectral position between the stop bands of two DFB sections. We fabricated a novel structure in which two gratings were located one over and one under the active layers. Each grating structure was independently defined in processing so that detuning, which is the prerequisite for self-pulsation, could be easily controlled. Observing various self-pulsating phenomena in these devices under several detuning conditions, we characterized the phenomena as dispersive Q-switching, mode beating, and self-mode-locking.

• Proceedings of the Korean Magnestics Society Conference
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• 2004.12a
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• pp.175-176
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• 2004

An integrated waveguide optical isolator by wafer direct bonding has been studied. The isolation ratio was found to be 2.9dB in our device. We found that wafer direct bonding between the InP and GGG is effective for the integration of a waveguide optical isolator.

• Electronics and Telecommunications Trends
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• v.24 no.6
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• pp.77-85
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• 2009

최근 북한의 미사일 발사시험과 이를 둘러싼 주변국들간의 군사력 강화 움직임이 한반도의 안보에 심각한 위협요소가 되면서 다시금 자주 국방의 필요성에 대한 경각심이 고취되고 있다. 국방기술의 첨단화는 과학기술의 발명에 전적으로 의존하여 향후 국가간 국방과학기술로서 기술력 우위 확보를 위한 치열한 경쟁이 가속화 될 것이다. 이에 우리나라도 미래지향적인 국방기술의 중점육성분야를 분류하고 분야별 해당하는 무기체계와 핵심기술의 기술지도를 주축하여 장기간에 걸친 국방연구개발계획의 실행을 지속해오고 있다. 향후 선진국과의 기술격차도 해소하고 나아가 기술우위를 점하게 되면 자주국방이 가능하게 되고 기술력의 수출까지 가능해질 것이다. 본 고에서는 국내 국방 무기체계 및 특히 국방전자 분야의 기술과 개발 동향에 대해 살펴보고자 한다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.6
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• pp.580-583
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• 2008

In this paper, we investigated the properties of chalcogenide glass thin films formed by photo-inducing for use in 1-dimensional photonic crystals. We used Ag-doped amorphous As-Ge-Se-S thin films which belongs in the chalcogenide materials having sensitive photoluminescence properties. The purpose of this experiment is to form the holographic lattice for 1-dimensional photonic crystals. The way in which photo-induce into the amorphous chalcogenide thin films is holographic lithography method. We confirmed the formation of diffraction lattice by sensing the existence of diffraction beam and measured the diffraction efficiency. The results suggest that there is an application possibility with photonic crystals.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.933-935
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• 1987

We have developed 140Mb/s and 565Mb/s muldexes as parts of a 565Mb/s Optical Fiber Transmission System. Bunched frame structures are used for these muldexes. In this paper we describe their frame synchronization performance.

• Journal of Integrative Natural Science
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• v.6 no.3
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• pp.183-186
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• 2013

Well defined 1-dimentional (1-D) photonic crystals of polystyrene replicas have been successfully obtained by removing the porous silicon from the free-standing rugate porous silicon/phenylmethylpolysiloxane composite film. Rugate porous silicon was prepared by an electrochemical etching of silicon wafer in HF/ethanol mixture solution. Exfoliated rugate porous silicon was obtained by an electropolishing condition. A composite of rugate porous silicon/phenylmethylpolysiloxane composite film was prepared by casting a toluene solution of phenylmethylpolysiloxane onto the top of rugate porous silicon film. After the removal of the template by chemical dissolution, the phenylmethylpolysiloxane castings replicate the photonic features and the nanostructure of the master. The photonic phenylmethylpolysiloxane replicas are robust and flexible in ambient condition and exhibit an excellent reflectivity in their reflective spectra. The photonic band gaps of replicas are narrower than that of typical semiconductor quantum dots.

• Journal of the Semiconductor & Display Technology
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• v.5 no.2 s.15
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• pp.1-5
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• 2006

The GaN thin film on the 8 periods InGaN/GaN multi-quantum well structure was grown on the sapphire substrate using metal-organic chemical vapor deposition. The nano-scaled triangular-lattice holes with the diameter of 150 nm were patterned on a polymethylmethacrylate blocking film using an electron beam nano-lithography system. The thin slab and two-dimensional photonic crystals with the thickness of 28 nm were fabricated on the GaN layer for the blue light diffraction sources. The photonic crystal with the lattice parameter of 460 nm enhances spectral intensity of photoluminescence indicating that the photonic crystals provides the source of nano-diffraction for the blue light of the 450-nm wavelength.

• Journal of the Optical Society of Korea
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• v.15 no.4
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• pp.398-402
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• 2011

In this paper, we have proposed a principle to design wideband, low dispersion and temperature stabilized slow light structure in slotted photonic crystal waveguide (SPCW). The infiltration of the silicon photonic crystal with polymer will enhance the slow light and increase the group index, whereas the different signs of thermo-optic coefficients of polymer and silicon make the proposed structure stable on temperature variation over $60^{\circ}C$ and improves the group index-bandwidth products of the designed structure. The SPCW structure is modified to maximize the slow light effect and minimize the dependence of the group index and hence the group velocity dispersion to temperature.