Development of selective excitation method with in-phase molecular vibration using double-peak spectrum 5-fs laser pulse

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K15512
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 32010:Fundamental physical chemistry-related
• Research Institution: Yokohama National University (2021); Kanagawa University (2019-2020)
• Principal Investigator: Hashimoto Sena 横浜国立大学, 大学院工学研究院, 日本学術振興会特別研究員 (30824932)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: フェムト秒パルスレーザー光 / 分子振動励起 / 分子振動実時間分光 / 光化学反応

Outline of Final Research Achievements

Using broadband 5-fs laser pulse whose duration is shorter than the molecular vibrational period, several modes of Raman active molecular vibrational modes can be simultaneously excited and the excited molecular vibrations starts with the same timing (initial phase of molecular vibration). In the present work, we have generated 5-fs laser pulse with spectrum of double peak whose energy gap is matched with a specific molecular vibrational mode. It enabled us to produce a wave packet only for the specific molecular vibration which selectively excite keeping the molecular vibration in phase. Then, we have measured time development of the molecular vibration to analyze relaxation process of molecular vibration. The selective excitation of the molecular vibration level has induced a corresponding chemical reaction.

Free Research Field

レーザー化学

Academic Significance and Societal Importance of the Research Achievements

レーザー発振が報告されて以来、レーザー光の特長を活かした化学反応制御が種々試みられてきた。本研究では、有機分子の特定の分子振動モードのみを選択的に励起可能な新規ダブルピーク型5-fsパルスレーザー光を発生させた。さらに、選択的に分子振動準位を励起することで、反応性を制御した。本手法が新たな反応制御手法になることを期待する。