Investigation of femtosecond optical delay and auto correlator in X-ray region

2013 Fiscal Year Final Research Report

• Project/Area Number: 23360038
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Applied optics/Quantum optical engineering
• Research Institution: The Institute of Physical and Chemical Research
• Principal Investigator: TAMASAKU Kenji 独立行政法人理化学研究所, 放射光科学総合研究センター, 専任研究員 (30300883)
• Project Period (FY): 2011-04-01 – 2014-03-31
• Keywords: X線自由電子レーザー / 非線形光学 / 内殻２重イオン化 / ２光子吸収 / パルス幅測定

Research Abstract

We investigate X-ray auto correlator to determine the duration of femtosecond pulses from X-ray free-electron lasers. We successfully observe double core-hole creation in krypton and direct two-photon absorption in germanium, which are indispensable two-photon processes for the auto correlator. We estimate the pulse duration to be 2.5 fs by analyzing the X-ray fluorescence spectrum from the double core-hole state. We find a competition between K-shell two-photon absorption and L-shell one-photon absorption. We analyze the pulse-energy dependence of two-photon absorption including the competition effect. Finally, we successfully reproduce the observed pulse-energy dependence, and determine the cross section of two-photon absorption. The competition determines the highest intensity for the auto correlator with two-photon absorption.

Research Products

• [Journal Article] X-ray two-photon absorption competing against single and sequential multiphoton processes (2014)
  • Author(s): K.Tamasaku, E.Shigemasa, Y.Inubushi, T.Katayama, K.Sawada, H.Yumoto, H.Ohashi, H.Mimura, M.Yabashi, K.Yamauchi, T.Ishikawa
  • Journal Title: Nature Photon. Volume: 8 Pages: 313-316
  • DOI: 10.1038/nphoton.2014.10
  • Peer Reviewed
• [Journal Article] Double Core-Hole Creation by Sequential Attosecond Photoionization (2013)
  • Author(s): K.Tamasaku, M.Nagasono, H.lwayama, E.Shigemasa, Y.Inubushi, T.Tanaka, K.Tono, T.Togashi, T.Sato, T.Katayama, T.Kameshima, T.Hatsui, M.Yabashi, T.Ishikawa
  • Journal Title: Phys. Rev. Lett. Volume: 111 Pages: 043001
  • DOI: 10.1103/PhysRevLett.111.043001
  • Peer Reviewed
• [Presentation] Experimental requirements for XFEL frozm X-ray nonlinear optics (2014)
  • Author(s): Kenji Tamasaku
  • Organizer: Workshop on Advanced X-ray FEL Development
  • Place of Presentation: DESY, Germany
  • Year and Date: 2014-05-21
• [Presentation] 結晶によるX線回折と分光器 (2014)
  • Author(s): 玉作賢治
  • Organizer: 第27回日本放射光学会年会・放射光科学合同シンポジウム
  • Place of Presentation: 広島国際会議場,広島
  • Year and Date: 2014-01-12
• [Presentation] Nonlinear response induced by focused X-ray laser (2013)
  • Author(s): Kenji Tamasaku
  • Organizer: The 12^<th> Symposium on X-ray Imaging Optics
  • Place of Presentation: 大阪大学中之島センター,大阪
  • Year and Date: 2013-11-19
• [Presentation] Nonlinear Optics in the Hard X-ray Region (2013)
  • Author(s): Kenji Tamasaku
  • Organizer: CLEO-PR&OECC/PS2013
  • Place of Presentation: 国立京都国際会館,京都
  • Year and Date: 2013-06-30
• [Presentation] X-ray nonlinear optics at SPring-8&SACLA (2013)
  • Author(s): Kenji Tamasaku
  • Organizer: Ringberg meeting on FELs
  • Place of Presentation: Schloss Ringberg, Germany
  • Year and Date: 2013-02-17
• [Presentation] 非線形応答が支配するXFEL利用研究 (2013)
  • Author(s): 玉作賢治
  • Organizer: 第26回日本放射光学会・放射光科学合同シンポジウム
  • Place of Presentation: 名古屋大学
  • Year and Date: 2013-01-13
• [Presentation] 非線形光学現象 (2012)
  • Author(s): 玉作賢治
  • Organizer: 放射光将来光源利用サイエンス若手シンポジウム
  • Place of Presentation: 東京大学
  • Year and Date: 2012-08-18
• [Remarks] ①X線の2光子吸収の観測に成功-数百ゼプト秒の間にほぼ同時に原子を2度打ち- ホームページ等
  • URL: http://www.riken.jp/pr/press/2014/20140217_1/
• [Remarks] ②X線を2回当てて「中空原子」の生成に世界で初めて成功-量子だるま落としで2段抜き- ホームページ等
  • URL: http://www.riken.jp/pr/press/2013/20130723_2/