title: Excited-state molecular vibration observed for a probe pulse preceding the pump pulse by real-time optical spectroscopy.
abstract: It is shown experimentally that the absorbance change observed in the "negative" time range, where probe pulse precedes pump pulse in real-time vibrational spectroscopy is induced only by the excited-state wave-packet motion as theoretically expected. Coherent molecular vibration of a polymer in the excited state was observed in the real-time trace without the effect of wave-packet motion in the ground state, which usually makes it difficult to ascribe the signal either to the ground state or to the excited state.
authors.affiliation: Department of Applied Physics and Chemistry and Institute for Laser Science, the University of Electro-communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan. kobayashi@ils.uec.ac.jp
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Juan
authors.initials: J
authors.lastname: Du
authors.forename: Wei
authors.initials: W
authors.lastname: Feng
authors.forename: Katsumi
authors.initials: K
authors.lastname: Yoshino