"Femtosecond Nonlinear Multidimensional Spectroscopy"
Graham R. Fleming
Department of Chemistry, UC Berkeley
Physical Biosciences Division, LBNL
Wednesday, January 21, 2004 - 11 AM -12 Noon in 375 LeConte Hall
Abstract
The photosynthesis apparatus of plants and photosynthetic bacteria
is an example of exquisitely efficient nanoscale engineering. Understanding the design
principles at work in such a system requires undoing of multiple averages (over time,
distance, energy) that render conventional spectroscopic measurements of
limited value. In this talk, I will describe a series of femtosecond nonlinear optical
experiments that my group has developed to peel back some of the layers of
average and provide views of theunderlying microscopic dynamics. In doing so, the
interplay of molecular interactions, energy disorder, spatial proximity and connectivity
become apparent. In addition to some techniques that have become fairly standard
over the past ten years or so, I will describe two new spectroscopic methods -
two-color photon echo spectroscopy and two-dimensional heterodyne spectroscopy -
and their potential for the experimental determination of the Hamiltonian of
complex multichromophore systems.
