Temperature dependence of optical near-field energy transfer rate between two quantum dots in nanophotonic devices.

We have obtained a simple numerical model that explains the temperature behavior of multi-quantum-dot (QD) nanophotonic devices whose operations are based on optical near-field (ONF) interactions between any two resonant QDs that are in thermal equilibrium. This model involves a set of coupled rate equations that govern the temporal behavior of the QDs' energy level occupancies. Under a certain operating condition, this simple model can substitute for the more complex density matrix (DM) approach in modeling the temperature dependence of the ONF energy transfer rate (R(ONF)) between any two resonant QDs in thermal equilibrium. The same applies for modeling the system state-filling time (tau(S)). Applying our simple model to a two-QD system, we have derived analytical formulas for the interdot and the intradot transfer rates at finite temperatures (T > or = 0). Furthermore, by assuming a unidirectional energy transport operating condition, we have also derived an analytic formula for calculating tau(S) for a two-QD system. To the best of our knowledge, this work is the first instance of reporting such analytic equations. Approximated values of tau(S) obtained from our simple analytic equation are in reasonable agreements with those calculated by the DM approach.