• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.109-112
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• 2003

Wavelength division multiplexing technology is a promising solution for the next generation optical networks. Optical buffer is a key component for optical packet switching system. It can be used to hold optical packets and to resolve the contention of optical packets. In this paper, we implemented a optical buffer using optical wavelength converters and demonstrated that optical packets are delayed successfully.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 센서 박막재료 반도체재료 기술교육
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• pp.111-118
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• 2002

A new lithium niobate optical modulator with a polymer buffer layer on Ni in-diffused optical waveguide is proposed for the fist time, successfully fabricated and examined at a wavelength of 1.3 mm. By determining the diffusion parameters of Ni in-diffused waveguide to achieve more desirable mode size which is well matched to the mode in the fiber, the detailed results on the achievement of high optical throughput are reported. In addition, the usefulness of polymer buffer layer which can be applicable to a buffer layer in Ni in-diffused waveguide devices is demonstrated. Several sets of channel waveguides fabricated on Z-cut lithium niobate by Ni in-diffusion were obtained and on which coplanar traveling-wave type electrodes with a polymer-employed buffer layer were developed by a conventional fabrication method for characterizing of electro-optical performances of the proposed device. The experimental results show that the measured half-wave voltage is of ~10 V and the total measured fiber-to-fiber insertion loss is of ~6.4 dB for a 40 mm long at a wavelength of =1.3 mm, respectively. From the experimental results, it is confirmed that the polymer-employed buffer layer in LiNbO3 optical modulator can be a substitute material instead of silicon oxide layer which is usually processed at a high temperature of over $300^{\circ}C$. Moreover, the fabrication tolerances by using polymer materials in LiNbO3 optical modulators are much less strict in comparison to the case of dielectric buffer layer.

• 한국광학회:학술대회논문집
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• 한국광학회 1999년도 제16회 광학 및 양자전자 학술발표회Proceedings of 16th Optics and Quantum Electronics Conference, 1999
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• pp.180-181
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• 1999

• 한국통신학회논문지
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• 제29권5A호
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• pp.514-520
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• 2004

WDM 네트워크에서 WDM 버퍼는 전광 패킷 스위칭 시스템을 구현하기 위한 핵심적인 요소 기술이다. 본 논문에서는 단일 루프형 전광 WDM 버퍼 구조를 제안하였으며, 이를 실험적으로 확인하였다. 제안된 구조는 NOLM과 피드백 루프로 구성되며, 제어 광 신호 (1553nm, 펄스 폭： 30㎱)에 의해 버퍼로부터 출력되기까지 단일 입력 펄스 (1550nm, 펄스 폭： 20㎱)를 약 40회 이상 버퍼링 (20${\mu}\textrm{s}$ 이상)할 수 있었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.24.1-24.1
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• 2009

The zinc oxide (ZnO) material as the II-VI compound semiconductor is useful in various fields of device applications such as light-emitting diodes (LEDs), solar cells and gas sensors due to its wide direct band gap of 3.37eV and high exciton binding energy of 60meV at room temperature. In this study, the ZnO nanorods were deposited onto homogenous buffer layer/Si(100) substrates by a hydrothermal synthesis. The Effects of the buffer layer annealing and post annealing temperature on the structural and optical properties of ZnO nanorods grown by a hydrothermal synthesis were investigated. For the buffer layer annealing case, the annealed buffer layer surface became rougher with increasing of annealing temperature up to $750^{\circ}C$, while it was smoothed with more increasing of annealing temperature due to the evaporation of buffer layer. It was found that the roughest surface of buffer layer improved the structural and optical properties of ZnO nanorods. For the post annealing case, the hydrothermally grown ZnO nanorods were annealed with various temperatures ranging from 450 to $900^{\circ}C$. Similarly in the buffer layer annealing case, the post annealing enhanced the properties of ZnO nanorods with increasing of annealing temperature up to $750^{\circ}C$. However, it was degraded with further increasing of annealing temperature due to the violent movement of atoms and evaporation. Finally, the buffer layer annealing and post annealing treatment could efficiently improve the properties of hydrothermally grown ZnO nanorods. The morphology and structural properties of ZnO nanorods grown by the hydrothermal synthesis were measured by atomic force microscopy (AFM), field emission scanning electron microscopy (SEM), and x-ray diffraction (XRD). The optical properties were also analyzed by photoluminescence (PL) measurement.

• 한국통신학회논문지
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• 제25권6A호
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• pp.862-869
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• 2000

스위칭 시스템에서 버퍼는 라우팅시 신호간의 충돌을 방지하기 위해 반드시 필요하다. 광 스위칭 시스템에서도 단순한 광 교차 접속(OXC) 이상의 교환 및 라우팅을 수행하기 위해서는 광 버퍼를 필요로 한다. 오늘날 광전송 시스템 및 광 네트워크는 WDM을 기반으로 형성되어 가고 있으며 따라서 광 스위칭 역시 WDM 기술에 기반을 둘 것이고 이에 필요한 광 버퍼도 WDM 신호를 처리할 수 있어야 한다. WDM 스위칭 시스템에서 동시에 동일 가입자로 라우팅된 WDM 신호들을 순차적으로 출력시키기 위해 WDM 광 출력 버퍼를 필요로 한다. 본 논문에서는 기존의 발표된 WDM 광 출력 버퍼에 비해 구조, 하드웨어, SNR 및 BER 특성이 개선된 새로운 구조의 WDM 광 출력 버퍼를 제안한다. 제안한 버퍼에 대한 특성 분석결과, 새로운 구조의 버퍼는 버퍼를 구성하는 광 게이트(반도체 광 증폭기)의 이득 ON-OFF 비율(Contrast ratio)이 30dB인 경우, BER 10-9을 만족하면서 255개의 WDM셀을 저장할 수 있음을 알 수 있다.

• The Korean Journal of Ceramics
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• 제4권1호
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• pp.9-14
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• 1998

Diamond-like carbon(DLC) films were deposited on buffer-layered ZnS substrates by radio frequency plasma enhanced chemical vapor deposition(RF-PECVD) method. Ge and GeC buffer layera were used between DLC and ZnS substrates to promote the adhesion of DLC on ZnS substrates. Ge buffer layers were sputter deposited by RF magnetron sputtering and $GeC^1$ buffer layers were deposited by same method except using acetylene reactive gas. The relatinship between film properties and deposition conditions was investigated using gas pressure, RF power and dc bias voltage as PECVD parameters. The hardness of DLC films were measured by micro Vickers hardness test and the adhesion of DLC films on buffer-layered ZnS substrates were studied by Sebastian V stud pull tester. The optical properties of DLC films on butter-layered ZnS substrates were characterized by ellipsometer and FTIR spectroscopy.

• Journal of the Optical Society of Korea
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• 제20권3호
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• pp.431-434
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• 2016

Tris-HCl buffer solution is extensively used in biochemistry and molecular biology to maintain a stable pH for biomolecules such as nucleic acids and proteins. Here we report on the high-precision THz dielectric spectroscopy of a 10 mM Tris-HCl buffer. Using a double Debye model, including conductivity of ionic species, we measured the complex dielectric functions of Tris-HCl buffer. The fast relaxation time of water molecules in Tris-HCl buffer is ~20% longer than that in pure water while the slow relaxation time changes little. This means that the reorientation dynamics of Tris-HCl buffer with such a low Tris concentration is quite different from that of pure water.

• 열처리공학회지
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• 제28권6호
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• pp.291-295
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• 2015

IGZO single layer and $IGZO/TiO_2$ bi-layered films were deposited on glass substrate at room temperature with radio frequency magnetron sputtering to investigate the effect of $TiO_2$ buffer layer on the electrical and optical properties of the films. For all deposition, the thickness of IGZO and $TiO_2$ Buffer layer was kept at 100 and 5 nm, respectively. In a comparison of figure of merit, IGZO films with a 5-nm-thick $TiO_2$ buffer layer show the higher figure of merit ($8.40{\times}10^{-5}{\Omega}^{-1}$) than that of the IGZO single layer films ($6.23{\times}10^{-5}{\Omega}^{-1}$) due to the enhanced optical transmittance and the decreased sheet resistance of the films. The observed results mean that a 5 nm thick $TiO_2$ buffer layer in the $IGZO/TiO_2$ films results in better electrical and optical performance than conventional IGZO single layer films.

• 대한전자공학회논문지TC
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• 제40권10호
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• pp.95-102
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• 2003

광 전송 네트워크의 스위칭 기술에서 자원 충돌 문제를 해결하기 위한 방법으로 버퍼링은 중요한 문제중 하나이다. 본 논문은 가변길이 광 패킷 스위칭에 있어서 Fiber Delay Line(FDL)을 사용한 광 버퍼의 dimensioning과 패킷의 손실률에 대하여 연구하였다. 우선 단단(single-stage) FDL 버퍼에서의 granularity와 버퍼 손실에 대한 관계를 고찰하고 간단한 구조의 다단(multi-stage) FDL 버퍼 구조를 제안하였다. 다단 FDL 버퍼는 구현 기술이나 경제성의 측면에서 현 시점에서는 실용성이 높지 않지만 본 논문에서는 미래에 실용화가 가능할 것이라는 가정 하에 다단 FDL 버퍼 구조들을 제안한다. 제안한 FDL 버퍼 구조에서 각 스테이지에 사용되는 지연 및 패스 라인의 소요량을 시뮬레이션을 통해 고찰하고 그 사용율에 근거하여 multi-stage FDL 버퍼를 dimensioning하였다. 또한 보다 실질적인 구조의 다단(multi-stage) FDL 버퍼를 제안하고 그 적합성을 버퍼 크기와 패킷 손실율의 관계를 통하여 연구하였다.