Optically switched energy transfer: Twin-beam off-resonance control

It is shown that, in the optical near field, the interaction of two polarized laser beams with different frequencies can promote a transfer of energy between suitably placed donor and acceptor particles, through a process that is rigorously forbidden in the absence of the laser light. The mechanism, which operates through stimulated Raman scattering by the donor-acceptor pair, is identified and characterized by quantum electrodynamical calculation. The results suggest efficiency levels comparable to conventional resonance energy transfer. Optical switching applications are envisaged.