• 제목/요약/키워드: $LiNbO_3$ crystal

검색결과 165건 처리시간 0.021초

Nd\2O3 첨가에 따른 화학양론조성 LiNbO3 단결정의 성장 및 형광특성 (Crystal Growth and Photoluminescence Property of Stoichiometric LiNbO3 Single Crystal Fiber by Addition of Nd2O3)

  • 서중원;윤석규;이성문;윤대호
    • 한국세라믹학회지
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    • 제39권10호
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    • pp.977-980
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    • 2002
  • Micro-pulling down법을 이용하여 $Nd_2O_3$가 첨가된 crack 등의 결함이 없는 화학양론조성의 $LiNbO_3$ 단결정을 직경 1 mm, 길이 30∼35 mm의 크기로 성장시켰다. Electron probe micro analysis를 이용하여 결정 내에 $Nd_2O_3$가 균일하게 분포되어있음을 확인하였다. 성장된 결정의 $Nd_2O_3$ 첨가에 따른 흡수 band를 관찰하였고 $Nd_2O_3$ 첨가량 변화에 따른 형광특성의 변화를 측정하였다.

Temperature Dependence of Mn2+ Paramagnetic Ion in a Stoichiometric LiNbO3 Single Crystal

  • Yeom, Tae Ho;Lee, Soo Hyung
    • Journal of Magnetics
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    • 제18권3호
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    • pp.221-224
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    • 2013
  • Electron paramagnetic resonance (EPR) spectra of $Mn^{2+}$ impurity ion in Stoichiometric $LiNbO_3$ single crystal (SLN) was investigated with an X-band EPR spectrometer in the temperature range of 3 K~296 K. The intensity of EPR spectrum of $Mn^{2+}$ ion was increased to 20 K and decreased again below 20 K as the temperature decreases. The zero-field splitting parameter D decreased as the temperature increases. It was suggested that $Mn^{2+}$ ion substitute for $Nb^{5+}$ ion instead of $Li^+$ ion. No changes for hyperfine interaction of $Mn^{2+}$ ion was obtained in the temperature range of 3 K~296 K.

Fe-LiNbO$_{3}$ 결정에서 광굴절격자의 비균일성에 의한 광학적 잡음의 영향 분석 (Analysis of optical noise influence due to inhomogeneity of photorefractive grating in Fe-LiNbO$_{3}$ crystal)

  • 안준원;최연숙;김남;이권연;강석열
    • 전자공학회논문지D
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    • 제35D권3호
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    • pp.91-97
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    • 1998
  • In a LiNbO$_{3}$ crystal, optical noise is caused by the inhomogeneity of crystal inside if the excess energy is incident on the crystal. In this paper, we experiemnt the influence of optical noise when it is applied for beam diffraction and optical information storage. And it is proposed the energy threshold level which is not affected by optical noise in Fe-LiNbO$_{3}$ crystal(0.02Wt.% doped, 10mm*10mm*10mm). The optical noise of crystal weremeasured as a function of the incident beam intensity(10mw, 5mw, 1mw, 0.5mw), direction in incident(orthogonal, left rotation, right rotation) and wavelength(514.5nm, 632.8nm).

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녹색 광 발진을 위한 주기적 분극 반전된 MgO : $LiNbO_3$ ridge waveguide 제작 (Fabrication of a periodically poled MgO : $LiNbO_3$ ridge waveguide for a green laser generation)

  • 양우석;권순우;송명근;이형만;김우경;구경환;윤대호;이한영
    • 한국결정성장학회지
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    • 제17권4호
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    • pp.151-155
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    • 2007
  • 녹색 광 발진을 위해 조화용융조성의 MgO가 첨가된 $LiNbO_3$ 결정을 이용하여 준위상정합 2차 조화파 도파로 소자를 제작하였다. 도메인 반전을 위해 +Z면에 주기적인 전극 패턴을 형성하였으며, 외부전계의 균일한 인가를 위해 LiCl 전해 용액을 사용하여 도메인을 반전 시켰다. 선택적 화학식각을 통해, 약 $6.8{\mu}m$의 분극 반전 주기를 확인 할 수 있었으며, $7{\mu}m$ ridge 높이와 $3{\mu}m$의 slap높이를 갖는 폭 $5{\mu}m$의 PPMgLN ridge-type 도파로 소자의 비선형 특성을 측정하였다.

$LiNbO_3$의 단결정 성장 (Single Crystal Growth of $LiNbO_3$)

  • 최종건;오근호
    • 한국세라믹학회지
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    • 제22권5호
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    • pp.43-46
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    • 1985
  • Constitutional supercooling due to concentration gradient at solid-liquid interface in the melt can be avioded by increasing rotational speed for growing $LiNbO_3$ single crystals from the stoichiometric melt. Growth conditions for high quality crystals were determined by rotational speed by which other growth parameters were adjusted.

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PZT압전세라믹을 이용한 SAW필터의 제작 (Fabrication of SAW filter using PZT ceramics)

  • 정연호;송준태
    • E2M - 전기 전자와 첨단 소재
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    • 제10권1호
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    • pp.1-7
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    • 1997
  • SAW filter has been used in mobile communication device, bandpass filter and resonator for merits )f miniaturization and high reliability. Materials for substrate mainly used single crystal such as LiNbO$_{3}$, LiTaO$_{3}$, ZnO. In this study, it was attempted that LiNbO$_{3}$ was substituted for piezoelectric ceramics(PZT4, PZT5A and PZT8) which had simple fabrication process because fabrication of crystal is difficult and it's cost is high. SAW filters were fabricated by the photolithography on piezoelectric ceramics substrates in order to compare their characteristics with LiNbO$_{3}$'s. The experimental value of center frequency was compared with theoretical one. The average difference of center frequency was 3.7%. PZT8 showed the best bandwidth properties among them. It is considered that PZT8 has higher mechanical quality factor and propagation velocity than others.

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${\mu}-PD$ 법으로 성장시킨 near-stoichiometric 조성 $Zn:LiNbO_3$ fiber 단결정 성장 및 광손상 특성 (Crystal growth and optical properties of near-stoichiometric $Zn:LiNbO_3$ fiber single crystal by ${\mu}-PD$ method)

  • 이호준;서중원;신동익;송원영;윤대호
    • 한국결정성장학회지
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    • 제16권6호
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    • pp.235-239
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    • 2006
  • Micro-pulling down$({\mu}-PD)$법을 이용하여 직경 $0.8{\sim}1.0mm$, 길이 $30{\sim}35mm$의 ZnO가 첨가된 near-stoichiometric $LiNbO_3$, 단결정을 성장하였다. 성장된 결정의 결정구조를 powder x-tay diffraction(XRD) patterns으로 확인하였고, electron probe micro analysis(EPMA)를 이용하여 결정내 Zn 이온들이 균일하게 분포되었음을 확인하였다. 또한 2 mol% 이상의 ZnO 첨가시 $OH^-$ 흡수밴드의 특성이 크게 변화함을 관찰함으로써 ZnO 첨가량에 일치한 역치(threshold)가 존재함을 확인하였다.