Further, since there are no optically-allowed transitions to or from |2 , population in this state reflects the cumulative population transferred to the excited states of MG through coupling to either the external field or to the dipole field of the CNP. Hence, the relative sink population in the isolated acceptor and coupled donor-acceptor systems can be used as a measure of RET efficiency. This differs from a common experimental measure of RET efficiency to acceptor fluorophores, which uses fluorescence enhancement of the acceptor to define a RET quantum yield per excitation event of the donor; 59 while we could adopt this measure in our simulations, we find the definition in terms of sink populations to be simpler in this case. Radiative relaxation channels, namely fluorescence, in MG may also included in the present model through the Lindbladian terms