• 제목/요약/키워드: Ti : Sapphire

검색결과 143건 처리시간 0.031초

RF마그네트론 스퍼터링법으로 제조한 $YBa_2Cu_3O_{7-x}$전도체 박막의 특성에 대한 기판의 영향 (Substrate effects on the characteristics of $YBa_2Cu_3O_{7-x}$ thin films prepared by RF magnetron sputtering)

  • 신현용;박창엽
    • E2M - 전기 전자와 첨단 소재
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    • 제8권1호
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    • pp.6-12
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    • 1995
  • High Tc superconducting YBa$_{2}$Cu$_{3}$$O_{7-x}$ thin films were prepared on various substrates by off-axis rf magnetron sputtering method to examine the substrate effects on the film structure and its R-T characteristics. The SEM analysis showed that the surface morphology of the grown YBa$_{2}$Cu$_{3}$O.sub 7-x/, film has different characteristic structure with different substrate used. The film on (100) SrTiO$_{3}$ substrate has critical current density of 3*10$^{5}$ A/cm$^{2}$ at 77K under zero magnetic field. The X-ray diffraction measurements revealed that the films on (100) SrTiO$_{3}$ substrate have mixed a-axis and c-axis normal to the substrate surface and the films on (100) MgO and ZrO$_{2}$/sapphire substrates have c-axis normal orientation to the substrate surface. However, YBa$_{2}$Cu$_{3}$$O_{7-x}$ films on (100) sapphire substrates showed no preferential orientation.ion.

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광자 결정 광섬유에서 펌프광원의 파장과 입력파워에 따른 초 광대역 광원 발생의 특성 (Characterization of Supercontinuum Generation as a function of Pump Wavelength and Intensity in Photonic Crystal Fiber)

  • 김종두;이기주;전민용;안성준;최용규
    • 한국광학회지
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    • 제16권6호
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    • pp.490-493
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    • 2005
  • 본 논문은 광자 결정 광섬유에서 100 fs의 펄스 폭을 갖는 펌프 광원의 파장과 입력파워에 따른 초 광대역 광원 생성에 대해 실험적으로 연구하였다. 적절한 파라미터들을 조절함으로써 광 스펙트럼 진폭의 균일함이 10 dB 이내에서 약 750 nm의 스펙트럼 폭을 갖는 초 광대역 광원을 얻어냈다. 사용한 광자 결정 광섬유의 길이는 2 m였고, 펌프광원으로는 모드 록킹된 Ti:Sapphire laser를 사용하였다. 또한, 펌프 광원의 여러 가지 변수들을 바꿔줌으로써 초 광대역 광원의 다양한 스펙트럼 현상을 조절할 수 있었다.

Efficient keV X-ray Generation from Irradiation of in-situ Produced Silver Clusters by Ti:sapphire Laser Pulses

  • Chakravarty, U.;Naik, P.A.;Kumbhare, S.R.;Gupta, P.D.
    • Journal of the Optical Society of Korea
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    • 제13권1호
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    • pp.80-85
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    • 2009
  • An experimental study of energy absorption and x-ray emission from ultrashort laser pulse irradiation of in-situ produced solid clusters has been performed. Silver clusters produced by a 30 mJ, 300 ps laser pulse were irradiated up to an intensity of $3{\times}10^{17}\;W/cm^2$ by a 70 mJ, 45 fs compressed laser pulse from the same Ti:sapphire laser. Absorption of the laser light exceeding 70% was observed, resulting in an x-ray yield (>1 keV) of ${\sim}60{\mu}J$ pulse. This may constitute a much simpler means of intense x-ray generation using ultrashort laser pulses as compared to the irradiation of structured / pre-deposited cluster targets, and it offers higher x-ray conversion efficiency than that from gas clusters and planar solid targets.