Starting from the Riemann-Silberstein formulation of classical
electrodynamics the Schrödinger equation for the photon energy wave
function is discussed. Hereafter, a propagator description of the
space-time emission of a polychromatic photon from an atom is presented,
paying particular attention to the near-field electrodynamics. When the
atom is embedded in a solid-state plasma the photon emission process can
be dramatically modified. Limiting the analyses to solid-state plasmas
exhibiting translational and rotational symmetry, the near-field
atom-photon-plasma interaction is studied paying particular attention to
the plasmariton and plasmon excitation processes. It is shown that the
transverse and longitudinal parts of the plasma-screened field propagator
link in a direct manner to the free-photon propagator and the longitudinal
near-field photon propagator. The necessity of keeping both the transverse
and longitudinal parts of the plasma screening in a rigorous description
of near-field electrodynamics is demonstrated.