• 제목/요약/키워드: Quantum-well

검색결과 675건 처리시간 0.045초

빛에 의한 공명투과다이오드 진동자의 주파수 변조 특성 (Optical modulation characteristics of resonant tunneling diode oscillator)

  • 추혜용;이일희
    • 전자공학회논문지A
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    • 제33A권10호
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    • pp.139-143
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    • 1996
  • We report on the static and dynamic characteristics of optically modulated resonant tunneling diode oscillator (RTDO) formed in double-barrier quantum-well structure. Under the illumination of Ti:Sapphire laser, the dc current-voltage (I-V) curves of RTDO shifted towared lower voltages. This characteristic was found to odify the series resistance, negtive differential resistance, capacitance, and the inductance of the RTDO. As a result, the resonant frequency of TRDO centered at 5.302 GHz was found to decrease about 20 MHz under the laser illumination. At a constnat bias voltage, the oscillation frequency decreased linearly as the laser power was increased.

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Modelling the Mode Behavior of Circular Vertical-Cavity Surface-Emitting Laser

  • Ho, Kwang-Chun
    • International Journal of Internet, Broadcasting and Communication
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    • 제4권2호
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    • pp.22-27
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    • 2012
  • The design characteristics of circular vertical-cavity surface-emitting lasers are studied by using a newly developed equivalent network. Optical parameters, such as the stop-band or the reflectivity of periodic mirrors and the resonance wavelength, are explored for the design of these structures. To evaluate the differential quantum efficiency and the threshold current density, a transverse resonance condition of modal transmission-line theory is also utilized. This approach dramatically reduces the computational time as well as gives an explicit insight to explore the optical characteristics of circular vertical-cavity surface-emitting lasers (VCSELs).

FDTD를 이용한 진행파형 Ridge-type CPW 다중 양자 우물 전계 흡수 변조기 분석 (Analysis of Traveling-wave Ridge-type CPW MQW EA-modulator using FDTD)

  • 이승진;이정훈;공순철;최영완
    • 한국광학회:학술대회논문집
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    • 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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    • pp.270-271
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    • 2000
  • Among many optical modulators, we are interested in traveling-wave(TW) multiple quantum well(MQW) electro-absorption modulator which can be used for wide-band applications, covering DC to 30GHz or higher frequencies. In this study, we simulate a 1.3mm InGaAs/lnGaAsP TW MQW EAM using the 3D Finite Difference-Time Domain (FDTD) method. We identify that several geometric factors affect Microwave charateristics. Our calculated data provide useful information to optimize and fabricate ridge-type TW CPW EAM.

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다중 언덕형 광도파로/양자우물의 WKB 고유방정식 (WKB eigenvalue equation for multiple graded-index waveguides/quantum-wells)

  • 김창민;임영준
    • 전자공학회논문지A
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    • 제33A권11호
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    • pp.120-127
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    • 1996
  • In the WKB analysis, we propose the new forms of the trial eigenfunctions which not only converge at the turning points but also approximate to the conventional WKB solutions away from the turning points. The eigenvalue equation of multiple waveguides with graded index profile are derived by using the proposed WKB analysis and the transfer matrix method. The drived equation sare represented in the recursive form. The results of the eigenvalue equation sare comapred with those of the FDM, one of the well-known computational methods, for a three-waveguide coupler.

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MQW electroabsorption modulator integrated with a tapered waveguide vertical interconnect

  • Han, Sang-Kook
    • Journal of the Optical Society of Korea
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    • 제1권1호
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    • pp.44-47
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    • 1997
  • The integration of a GaAs/AlGaAs multi-quantum well electroabsorption modulator and a tapered waveguide vertical direction optical interconnect has been performed without the complicated regrowth process. Zn impurity-induced layer disordering of MQW layer is used to achieve the energy transfer between SQW and MQW regions. Light coupled into a SQW region was transferred to an MQW region and an intensity modulation of 10 dB extinction ratio was demonstrated.