  We present a microscopic model for exciton-induced transparency (ExIT) in a
hybrid system comprised of an emitter resonantly coupled to a surface plasmon
in a metal-dielectric structure. We obtain an effective optical polarizability
of such a system with coupling between the system components expressed in terms
of energy transfer rates. We demonstrate that, in the weak coupling regime, the
underlying mechanism of ExIT is the energy exchange imbalance between the
plasmon and the emitter in a narrow frequency region. We derive in analytic
form a frequency-dependent function that accurately describes the shape and
amplitude of the transparency window in scattering spectra, supported by
numerical calculations.
