Superfluorescence, free-induction decay, and four-wave mixing: experimental and numerical studies of the propagation of free-electron laser pulses through dense atomic/ionic media

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K12636
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 80040:Quantum beam science-related
• Research Institution: National Institutes for Quantum Science and Technology
• Principal Investigator: Harries James 国立研究開発法人量子科学技術研究開発機構, 関西光科学研究所 放射光科学研究センター, 上席研究員 (30416383)
• Co-Investigator(Kenkyū-buntansha): 久間 晋 国立研究開発法人理化学研究所, 開拓研究本部, 専任研究員 (50600045)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 自由電子レーザー / 超蛍光 / ヘリウム / コヒーレンス / 量子光学

Outline of Final Research Achievements

The scientific goal of the main focus of this research is the use of free-electron laser light sources to extend quantum optical effects well-established at visible wavelengths to the extreme-ultraviolet and shorter. Of particular interest is the phenomenon of "superfluorsecence", which is sensitive to the coherence of the light source used and also to coherence developed from dynamics within the medium. In earlier work we indirectly observed this phenomenon at short wavelengths (164 nm, 30.4 nm), and the goal was to directly observe the superfluorescence emissions in the time domain and compare with numerical simulations. A further goal is to explore routes to extending the observations to even shorter wavelengths.
We were successful in observing the 164 nm superfluorescence in the time domain, and comparing it with numerical simulations.

Free Research Field

原子分子物理学

Academic Significance and Societal Importance of the Research Achievements

学術的:X線領域における量子効果は様々な光源と様々な物質で研究の対象となっている。本研究ではその光源の一つである自由電子レーザーのコヒーレンス性に敏感な現象に注目し、今後の光源利用、手法開発に貢献できた。
社会的:「量子」をキーワードとした技術開発、手法開発は今後大きなテーマとなる。本研究ではその開発のためのプローブである自由電子レーザー光源の量子性の一つであるコヒーレンスと物質のコヒーレンス性に注目し、今後の研究方針や研究基盤に貢献できた。