So we see that
the two excited dipoles corresponding to the S0® S1and the S0® S2transitions may be oriented at an arbitrary
angle- in the extreme case this angle
could be 90o.After the excitation
process, however, regardless of whether the absorption process corresponded to
the S0® S1or the S0® S2transition, rapid thermalization leaves the
excited fluorophore in the S1level.The orientation of the excited dipoles will thus now possess a
different average orientation than the absorption dipoles originally
photoselected by the exciting light.