Electric Dipole Coupling in Optical Cavities and Its Implications for Energy Transfer, Upconversion and Pooling

TL;DR

This paper derives analytic expressions for electric dipole coupling in optical cavities, revealing how cavity geometry influences energy transfer processes and their sensitivity to donor-acceptor separation.

Contribution

It provides a theoretical framework connecting cavity geometry with exciton energy transfer, highlighting the impact on dipole coupling and separation dependence.

Findings

Near-field separation dependence remains unchanged by cavities.

Cavities can significantly alter dipole-dipole coupling strength.

Intermediate cavity sizes reduce separation sensitivity, enhancing energy transfer.

Abstract

Resonant energy transfer, energy transfer upconversion, and energy pooling are considered within optical cavities to elucidate the relationship between exciton dynamics and donor/acceptor separation distance. This is accomplished using perturbation theory to derive analytic expressions for the electric dipole coupling tensors of perfect planar and rectangular channel reflectors---directly related to a number of important energy transfer processes. In the near field, the separation dependence along the cavity axis is not influenced by the cavity and is essentially the same as for three-dimensional, free space. This is in sharp contrast to the reduced sensitivity to separation found in idealized low-dimensional settings. The cavity dynamics only correspond to their reduced dimensional counterparts in the far field where such excitonic processes are not typically of interest. There is an intermediate regime, though, where sufficiently small cavities cause a substantial decrease in separation sensitivity that results in one component of the dipole-dipole coupling tensor being much larger than those of free space.