Abstract

The light-harvesting (LH) pigment-proteins of photosynthetic purple bacteria have been extensively studied with picosecond¹ and now recently with femtosecond² pulses. LH pigments are organized in small minimum units of 2-4 polypeptides holding about the same number of chromophores, which aggregate to form the network of the intact antenna. Energy transfer between minimum units is believed to occur in a noncoherent hopping fashion. Interaction within a unit is probably quite strong and spectral evidence suggest that it should be characterized as strong exciton interaction leading to the formation of delocalized exciton states. In this report we will mainly be concerned with the ultrafast dynamics within such a minimum unit.

© 1994 IEEE