| Project/Area Number |
04452049
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物性一般（含極低温･固体物性に対する理論）
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| Research Institution | The University of Tokyo |
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Principal Investigator |
MATSUOKA Masahiro ISSP, Univ.Tokyo, Professor, 物性研究所, 教授 (10013476)
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| Co-Investigator(Kenkyū-buntansha) |
BABA Motoyoshi ISSP, Univ.Tokyo, Technical Assistant, 物性研究所, 教務職員 (60159077)
TOKUNAGA Eiji ISSP, Univ.Tokyo, Research Associate, 物性研究所, 助手 (70242170)
久我 隆弘 東京大学, 教養学部, 助教授 (60195419)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 1993: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1992: ¥3,700,000 (Direct Cost: ¥3,700,000)
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| Keywords | Two-photon interference / Michelson interferometer / Femtosecond pulse / Ultrafast Measurement / Coherence time / Pulse width / Fluorescence lifetime / Laser pulse / レーザーパルス |
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| Research Abstract |
We have proposed a two-photon-interference method to measure simultaneously the coherence time and pulse width of ultrafast optical pulses. Femtosecond measurement will be possible for optical pulses of very wide wavelength regions without limit in time resolution and at very low intensity photon-counting levels.
Two outputs from a Michelson interferometer are detected by two detectors, and coincidences are counted by varying the optical path difference. When the path difference is zero, the counting rate decreases, and produces a narrow dip having the width of the coherence time and a wide dip having the width of the order of the pulse width.
We have succeeded in measuring dye-laser pulses, scattered pulses from fine powder Basso scattered pulses from colloidal emulsion (diluted milk) and fluorescence of Nile Blue dye solution in dimethylaniline. As the variation of the measurement, two samples of BaSO_4, or the emulsion are placed in the two arms of the interferometer. We succeeded in measuring the wide dip alone which is favorable when we want to know the pulse width (or pulse shape) alone. However, it is thus far not possible in the case of the fluorescence. Further investigation is needed to reveal the reasons.
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