Hole-burning study of exciton migration and pigment-protein interaction inphotosynthetic systems

Spectral hole burning enabled to determine excited state lifetimes T-1 calc ulated from widths delta(ZPH) Of resonant zero phonon holes. Values of delt a(ZPH) reflected ultra-fast exciton migration within the photosystem II rea ction centers containing (5 and 6) chlorophylls a, (2) pheophytines a and ( 1) beta-carotene. This technique moreover provided Debye-Waller factor x an d mean frequency of protein phonons Omega, which characterized the pigment- protein interactions. The resonant holes were observed together with their vibronic satellites burnt both into absorption and fluorescence spectra of the reaction centers. The phenomenon of laser induced hole-filling of the p rimary hole after the burning of the secondary holes at different wavelengt hs, was used to study the role of fast de-excitation processes in hole burn ing. (C) 1999 Elsevier Science B.V. All rights reserved.