The observed coherences can therefore be attributed to a vibronic, or exciton-phonon type coupling, where vibrational modes of the molecule are associated with the geometry change between the molecule's ground and excited electronic states. It should be noted that although very similar BBPP data between the chromophore and LHC were obtained, the presence of electronic couplings between the chromophore units or the pillar remain unclear. The signals associated with these couplings may be outside the detection capabilities of the instrument. The pump and probe laser bandwidth targets the low-energy electronic transitions of the chromophore, covering only the ground-state bleach and stimulated emission bands. The resolution of coherences is limited at high frequencies by the 24-fs laser pulse duration, and at low frequencies by the maximum available pump-probe delay time of ∼1 ps.