Figure 2.

First, a pump pulse excites a population of the LH1 B875 band to its first excited state. The red wing of this state is then dumped by a resonant pulse at 940 nm. Selected early time-gated difference spectra show an ultrafast exciton reequilibration process of ∼500 fs with an oscillatory component of ∼150 fs. The pump-probe spectrum (PP) is added as a reference. The time reported is from the dump moment (T = 1 ps). PDPmPPmDP refers to the difference signal, pump-dump-probe minus pump-probe minus dump-probe, and PP refers to pump-probe.