Optically controlled energy transfer in stacked and coplanar polycyclic chromophores

In the search for enhanced control over the process of resonance energy transfer in multichromophore molecular systems, all-optical mechanisms offer many significant advantages over other systems. One recently conceived scheme, based on the optical switching of energy transfer, is achieved by coupling a normally forbidden decay transition with pulses of off-resonant laser light. Earlier work has suggested that such systems could offer levels of efficiency that might approach those associated with the usual Forster mechanism. In this Letter, the ab initio results of specific calculations on stacked and coplanar polycyclic chromophores are reported. The results show that by judicious choice of electronic state and laser wavelength, much higher levels of efficiency are achievable. A possible scheme for the implementation of such a system is discussed with regard to its potential use in energy harvesting and optical switching applications. © 2010 American Chemical Society.