Single and dual beam optical switching of resonance energy transfer

Abstract

Through photonic mechanisms based on near-field coupling, laser radiation can engage with resonant energy transfer in a variety of suitably designed materials and molecular structures. Energy that has been acquired, through the initial absorption of resonant laser light, undergoes transfer between chromophores only on the throughput of off-resonant light, the process known as laser-assisted resonance energy transfer. The comprehensive results that are presented here extend and generalize the theory for both single and dual beam configurations, producing results that are applicable to media of various types including doped crystals, heterogeneous multichromophore solids, and solutions. The detailed principles, here explained in terms of both energetics and optical selection rule criteria, are specifically illustrated for a variety of materials. It is shown how general application of the theory can facilitate the elucidation of experiments, by clearly interpreting the effects of laser polarization manipulation. On further analysis of the photophysical mechanisms it is also demonstrated that such effects represent an entirely practicable basis for optical switching and logic gate operation. The additional polarization selectivity afforded by a two-beam setup proves to allow the most complete system control. With such a configuration, there is considerable promise for the realization of new optically driven logic and molecular devices.

Optically controlled resonance energy transfer: Mechanism and configuration for all-optical switching

“…This condition requires the transition dipole moments of the donor and acceptor, and their mutual displacement vector, to be mutually perpendicular-thus excluding a Förster process that would otherwise be possible on symmetry and energetic grounds. 48 By application of the off-resonant laser beam the transfer of energy is activated, effecting all-optical switching action.…”

Laser-Controlled Fluorescence in Two-Level Systems

“…an overall process whose quantum amplitude is determined by third-order perturbation theory. Similar effects occur in connection with resonance energy transfer, as numerous studies have shown; [29][30][31][32][33][34][35][36][37][38] nonetheless in contrast to the perturbations that can be brought into effect by a static field, the leading orders of which arise in second-order, i.e. linear in both the emitted and the applied field.…”

Resonance Energy Transfer: Theoretical Foundations and Developing Applications

“…It has been suggested that these and other principles concerning the effect of static electric fields on coupled quantum dots may have an important role to play in quantum logic applications. Andrews has recently proposed a system in which the simultaneous delivery of laser pulses, with two differing off-resonant frequencies, might achieve a similar purpose, 101,102 while other studies currently underway are beginning to explore novel nanomechanical effects produced by the action of RET. 103 …”