Control of the electronic energy transfer pathway between two single fluorophores by dual pulse excitation.
We report on the control of the energy transfer pathway in individual donor-acceptor dyads by proper timing of light pulses matching the donor and acceptor transition frequencies, respectively. Excitation of both chromophores at virtually the same time induces efficient singlet-singlet annihilation, whereby excitation energy effectively flows from the acceptor to the donor. The dual pulse excitation scheme implemented here allows for all-optical switching of the fluorescence intensity at the single-molecule level. The population of higher excited states at the donor site was found to significantly increase the photobleaching probability.
Institut für Physikalische Chemie, Johannes Gutenberg-Universität Mainz, Jakob-Welder-Weg 11, 55128 Mainz, Germany.
Burkhard
B
Fückel
Gerald
G
Hinze
Fabian
F
Nolde
Klaus
K
Müllen
Thomas
T
Basché