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Control of coherence length of a single photon emitted from a microcavity

Research Project

Project/Area Number 16560032
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Applied optics/Quantum optical engineering
Research InstitutionThe University of Electro-Communications

Principal Investigator

UJIHARA Kikuo  The University of Electro-Communications, Faculty of Electro-Communications, Professor, 電気通信学部, 教授 (90017351)

Project Period (FY) 2004 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2005: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2004: ¥2,600,000 (Direct Cost: ¥2,600,000)
Keywordssingle photons / coherence length / Mach-Zhender interferometer / high Q microcavity / dye-microcavity system / マイクロキャビティ / 高Qキャビティ / ローダミン6G / マッハーツェンダー干渉計 / 光子 / 光子コヒーレンス / コヒーレンス長測定 / 二次コヒーレンス度 / 光子計測 / 光子統計生成モデル
Research Abstract

1.In order to obtain a single photon with a Fourier transform limit character, we have investigated a method wherein a planar microcavity with a high quality factor is employed so as to make the spectrum of the emitted photon is mostly determined by the narrow path band of the cavity. For this purpose, we have designed a planar microcavity with two high reflectivity mirrors of power reflectivity R=0.99999, which should yield a single photons of coherence length in the order of a cm. Actually fabricated mirrors had a power reflectivity R=0.99992, for which the expected photon coherence length was about 4mm.
2.With the above mirrors, we have constructed two planar microcavities : one contained a ethanol solution of dye Rhodamine6G with a concentration of 5×10^<-3> mol/L. Another contained a solution of concentration 5×10^<-4> mol/L For comparison we have also constructed a low Q planar microcavity utilizing mirrors of power reflectivity R=0.995 which contained a solution of 5×10^<-3> mol/ … More L. We have examined the intensity of the fluorescence of these three microcavities under pulsed excitation by second harmonic light of a YAG laser. The intensities of the three microcavities lowered successively by about 1.5 order of magnitude in the above order. The characteristics were fairly reproduced by a four level laser model with ample number of emitting molecules. The excitation intensity range to obtain a single photon was determined.
3.In order to measure the coherence length of the single photon, we have constructed a Mach-Zhender interferometer containing a corner cube that could be scanned by a stepping motor with resolution about 40nm. The overall size of the interferometer was about 50cm×40cm. Because the coherence length of the emitted photon was expected in the range of mms, it was needed that the path lengths in the interferometer should coincide within a mm. Thus, we have used a modulated semiconductor laser that had a coherence length in the order of a few cm and, by a repeated measurement of the interference visibility, could determined the zero-path difference position of the corner cube with an accuracy in the range of a mm.
4.We have given a theoretical photon number distribution for the fluorescence in the above experiments.
5. We are at the stage where we can examine the coherence length of the emitted single photons. There we will need to construct a photon counting system that allows the measurement of the single photon wavefunction by use of the Mach-Zhender interferometer. Less

Report

(3 results)
  • 2005 Annual Research Report   Final Research Report Summary
  • 2004 Annual Research Report
  • Research Products

    (8 results)

All 2006 2004

All Journal Article (8 results)

  • [Journal Article] Interference effects in the spontaneous emission from two initially excited atoms2006

    • Author(s)
      Zhao Haizhen, Kikuo Ujihara
    • Journal Title

      Journal of Modern Optics 53

      Pages: 835-855

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Model Calculation of Photon Number Distribution for Optically Pumped Single-Photon Source2006

    • Author(s)
      K.Ujihara
    • Journal Title

      Jpn.J.Appl.Phys. pt.2,45

      Pages: 184-186

    • NAID

      10018159139

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Distribution for Optically Pumped Single-Photon Source2006

    • Author(s)
      K.Ujihara
    • Journal Title

      Jpn.J.Appl.Phys., pt.2 45

      Pages: 184-186

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Interference effects in the spontaneous emission from two initially excited atoms2006

    • Author(s)
      Zhao H., K.Ujihara
    • Journal Title

      Journal of Modern Optics vol.53

      Pages: 835-855

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Model Calculation of Photon Number Distribution for Optically Pumped Single-Photon Source2006

    • Author(s)
      K.Ujihara
    • Journal Title

      Jpn.J.Appl.Phys. pt.2, vol.45

      Pages: 1884-186

    • NAID

      10018159139

    • Related Report
      2005 Annual Research Report
  • [Journal Article] The field intensity associated with spontaneous emission from two initially excited atoms2004

    • Author(s)
      Zhao Haizhen, K.Ujihara
    • Journal Title

      Opt.Commun. 24-/1-3

      Pages: 153-167

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] マイクロキャビティによる単一光子の発生2004

    • Author(s)
      東秀樹, 氏原紀公雄
    • Journal Title

      第10回量子情報技術研究会資料 QIT2004

      Pages: 155-158

    • Related Report
      2004 Annual Research Report
  • [Journal Article] The field intensity associated with spontaneous emission from two initially excited atoms2004

    • Author(s)
      Zhao Haizhen, Kikuo Ujihara
    • Journal Title

      Optics Communications 240

      Pages: 153-167

    • Related Report
      2004 Annual Research Report

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Published: 2004-04-01   Modified: 2016-04-21  

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