Observation of laser-induced off-resonance intermolecular electronic energy transfer

We report the observation of off-resonance electronic energy transfer from an excited rhodamine 6G molecule to an azulene molecule in solution. The process requires the coupling of the radiation field in the transfer process. We demonstrate that the relation Y_A I^1/2 between the acceptor's induced fluorescence intensity and the laser intensity, predicted by Jortner et al. is observed.