Generation of intense isolated attosecond pulses and their application to attosecond electron dynamics measurement

2018 Fiscal Year Final Research Report

• Project/Area Number: 26220606
• Research Category: Grant-in-Aid for Scientific Research (S)
• Allocation Type: Single-year Grants
• Research Field: Optical engineering, Photon science
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Midorikawa Katsumi 国立研究開発法人理化学研究所, 光量子工学研究センター, センター長 (40166070)
• Research Collaborator: Nabekawa Yasuo ; Takahashi Eiji ; Okino Tomoya ; Morishita Touru
• Project Period (FY): 2014-05-30 – 2019-03-31
• Keywords: アト秒パルス / 超短パルスレーザー / 高次高調波 / 非線形波長変換

Outline of Final Research Achievements

We have developed high-energy three-color optical waveform synthesizer consisting of the 800 nm main, 1300 nm signal and 1900 idler pulses by upgrading our original 2-color excitation method. By focusing the three color pulses into Ar gas cell. an isolated attosecond pulses energy of 240 nJ with a pulse duration of 140as at a central wavelength of 60eV was achieved. The attained peak power of 1.7 GW was intense enough to implement attosecond pump - attosecond probe experiments. In addition, we have demonstrated two-color simultaneous operation of 3 MHz high harmonics with a high-pulse-energy Yb:YAG thin disk ring-type oscillator. The harmonic order in each port can be independently controlled by choosing an appropriate gas for each port. Our method paves the way to MHz repetition-rated high-power XUV sources for multi-user or multi-color experiments.

Free Research Field

量子エレクトロニクス

Academic Significance and Societal Importance of the Research Achievements

本研究で達成された単一アト秒パルスのピークパワーは、1.7GWにも達しており、これは2光子過程を誘起するに十分な強度であり、これによってアト秒ポンプ-アト秒プロー実験が可能となる。一方、この高強度アト秒パルスの発生のために開発された低繰り返し高エネルギーレーザーのためにCEP安定化技術や時空間制御技術は、今後の高度物理に新たな展開をもたらすものと期待される。また、マルチポート動作のMHz級の超高繰り返し高調波光源は、シンクロトロン放射光とX線自由電子レーザーのギャップを埋め、超高速光電子分光やコインシデンス計測を利用した材料開発や化学反応研究に画期的な進展をもたらすであろう。