Ultrafast coherent spectroscopic investigation on photosynthetic pigment chlorophyll a utilizing 20 fs pulses

Vibrational dynamics of the photosynthetic pigment chlorophyll a in solution have been investigated by degenerated three-pulse four-wave mixing spectroscopies (transient grating and photon echo) using 20 fs pulses. Real-time wave-packet motions of intramolecular vibrations were clearly observed in four-wave mixing signals. Twelve vibrational modes due to chlorophyll a in the region of energy ranging from 200 to 1400 cm(-1) were found in the Fourier transform power spectra of coherent oscillations. We demonstrate that a specific light-matter interaction can be enhanced by a control of the temporal separation between the first and second pulses. (C) 2015 Elsevier B.V. All rights reserved.