title: Enhancement and suppression of vibrational coherence in degenerate four-wave-mixing signal generated from dye-doped polymer films.
abstract: Vibrational coherence in the degenerate four-wave-mixing (DFWM) signal generated from polymer films doped with a dye, oxazine 4 (Ox4), at 10 K was investigated. It was found that the amplitudes of some low-frequency oscillations (<400 cm(-1)) were enhanced when the delay between the first and second femtosecond pulses was set out of phase with the oscillation period. Frequency and reorganization energy dependence was investigated by computer simulation based on the response function formalism which considers all the possible Liouville space pathways for the DFWM signal. It was revealed that low-frequency oscillations with weak coupling to the optical transition can be enhanced in the stimulated photon echo signal compared to the transient grating signal.
authors.affiliation: Division of Frontier Materials Science, Graduate School of Engineering Science, and Research Center for Materials Science at Extreme Conditions, Osaka University, Toyonaka, Osaka 560-8531, Japan. nagasawa@cobalt.chem.es.osaka-u.ac.jp
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nagasawa
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Mori
authors.forename: Yukako
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyasaka
authors.forename: Tadashi
authors.initials: T
authors.lastname: Okada