  We determine the optical response of a thin and dense layer of interacting
quantum emitters. We show that in such a dense system, the Lorentz redshift and
the associated interaction broadening can be used to control the transmission
and reflection spectra. In the presence of overlapping resonances, a
Dipole-Induced Electromagnetic Transparency (DIET) regime, similar to
Electromagnetically Induced Transparency (EIT), may be achieved. DIET relies on
destructive interference between the electromagnetic waves emitted by quantum
emitters. Carefully tuning material parameters allows to achieve narrow
transmission windows in otherwise completely opaque media. We analyze in
details this coherent and collective effect using a generalized Lorentz model
and show how it can be controlled. Several potential applications of the
phenomenon, such as slow light, are proposed.
