Resonance energy transfer in the presence of a spherical cavity and dispersive substrate

Resonator cavities are known to influence the rate of energy exchange between nearby emitters due to their local modifications of the electromagnetic density of states. The emitters' positions, orientations, and detuning relative to each other and to their cavity environment all affect the degree to which energy transfer is enhanced or suppressed. However, the role of the underlying substrate sometimes used to support the cavity is often underestimated. Here, the authors model the interaction between a pair of emitters in the presence of a composite spherical cavity-substrate system and demonstrate that the resonant features of the substrate may dramatically influence the resulting density of states and energy transfer rate.