  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.
