VIBRATIONAL DYNAMICS IN THE LIGHT-HARVESTING COMPLEXES OF THE PHOTOSYNTHETIC BACTERIUM RHODOBACTER-SPHAEROIDES

Using almost-equal-to 40 fs pulses we have observed coherent nuclear m otions in intact membrane bound photosynthetic light-harvesting pigmen t-protein complexes. Computer simulations based on the harmonic Franck -Condon approximation and the Langevin equation describe qualitatively well the temperature and pulse wavelength dependence of the oscillati ons, indicating the possibility to observe higher harmonics of the fun damental frequency of the mode when exciting and probing in the blue s ide of the spectrum.