1. Volume 95, Issue 2, Pages 847-856 (July 2008)
Visualization of Excitonic Structure in the Fenna-Matthews-Olson Photosynthetic Complex by Polarization-Dependent Two-Dimensional Electronic Spectroscopy 
Elizabeth L. Read, Gabriela S. Schlau-Cohen, Gregory S. Engel, Jianzhong Wen, Robert E. Blankenship, Graham R. Fleming 
Biophysical Journal 
Volume 95, Issue 2, Pages (July 2008)
DOI: /biophysj
Copyright © 2008 The Biophysical Society Terms and Conditions

2. Figure 1
Real 2D spectra at 77K of FMO from P. aestuarii. Spectra shown from left to right are total, rephasing, and nonrephasing signals at T=0 (top) and T=400fs (bottom). All spectra are normalized to unity. The T=0 nonrephasing spectrum clearly shows distinctive diagonal peaks and crosspeaks not apparent in the rephasing spectrum, and energetic relaxation out of the upper band is visible in the nonrephasing spectrum at T=400fs.
Biophysical Journal  , DOI: ( /biophysj )
Copyright © 2008 The Biophysical Society Terms and Conditions

3. Figure 2
Rephasing (top) and nonrephasing (bottom) absolute magnitude 2D spectra of FMO from P. aestuarii at T=400fs, measured with polarizations 〈45°, −45°, 0°, 0°〉 (left) and 〈75°, −75°, 0°, 0°〉 (right) of laser pulses 1, 2, 3, and 4, respectively. The nonrephasing spectra show distinct spectral features under the two polarization conditions that can be used to obtain excitonic structural information. The strong crosspeak at (λτ=804nm, λt=814nm) in the 〈75°, −75°, 0°, 0°〉 nonrephasing spectrum is indicative of excitation energy transfer.
Biophysical Journal  , DOI: ( /biophysj )
Copyright © 2008 The Biophysical Society Terms and Conditions

4. Figure 3
Theoretical and experimental nonrephasing spectra of FMO from P. aestuarii at T=400fs and 77K. (Top row, left to right) Theoretical 〈0°, 0°, 0°, 0°〉, 〈45°, −45°, 0°, 0°〉, and 〈75°, −75°, 0°, 0°〉 2D spectra. (Top right) Experimental and theoretical linear absorption spectra in black and red, respectively; the dotted line indicates the laser spectrum of pulses used to measure 2D spectra. (Bottom row, left to right): Experimental 〈0°, 0°, 0°, 0°〉, 〈45°, −45°, 0°, 0°〉, and 〈75°, −75°, 0°, 0°〉 2D spectra.
Biophysical Journal  , DOI: ( /biophysj )
Copyright © 2008 The Biophysical Society Terms and Conditions

5. Figure 4
Energy transfer pathway orientational factor dependence on projection angle between exciton states for 〈45°, −45°, 0°, 0°〉 and 〈75°, −75°, 0°, 0°〉 polarization sequences (a). Below, calculated 2D nonrephasing dimer spectra at 400fs (top to bottom: all parallel, 〈45°, −45°, 0°, 0°〉 and 〈75°, −75°, 0°, 0°〉 polarizations) for a dimer with projection angle ϕ=5° (b) and ϕ=40° (c). The spectra in c reproduce more closely the behavior seen in the FMO polarization-dependent nonrephasing experiment because of the ∼40° relative orientation of the dominant transition dipoles.
Biophysical Journal  , DOI: ( /biophysj )
Copyright © 2008 The Biophysical Society Terms and Conditions

6. Figure 5
Qy transition dipole moments in the site basis (a) and exciton basis (b). The site basis is the case in the limit of negligible interchromophore couplings, and the transitions are localized on individual BChls. Coupling between BChls redistributes dipole strength among sites, resulting in different positions and orientations of the excitonic transition dipoles. The dominant peaks in the short-time 2D spectra arise from excitons 2 and 4 in red and cyan, respectively.
Biophysical Journal  , DOI: ( /biophysj )
Copyright © 2008 The Biophysical Society Terms and Conditions