  The dissipative quantum electromagnetics is introduced in a comprehensive
manner as a field-matter-bath coupling problem. First, the matter is described
by a cluster of Lorentz oscillators. Then the Maxwellian free field is coupled
to the Lorentz oscillators to describe a frequency dispersive medium. The
classical Hamiltonian is derived for such a coupled system, using Lorenz gauge
and decoupled scalar and vector potential formulations. The classical equations
of motion are derivable from the Hamiltonian using Hamilton equations. Then the
Hamiltonian is quantized with all the pertinent variables with the introduction
of commutators between the variables and their conjugate pairs. The quantum
equations of motion can be derived using the quantum Hamilton equations. It can
be shown that such a quantization scheme preserves the quantum commutators
introduced. Then a noise bath consisting of simple harmonic oscillators is
introduced and coupled to the matter consisting of Lorentz oscillators to
induce quantum loss. Langevin source emerges naturally in such a procedure, and
it can be shown that the results are consistent with the fluctuation
dissipation theorem, and the quantization procedure of Welsch's group. The
advantage of the present procedure is that no diagonalization of the
Hamiltonian is necessary to arrive at the quantum equations of motion. Finally,
we apply the quantization scheme to model spontaneous emission of a two-level
polarized atom placed above a dielectric cylinder that supports a bound state
in the continuum.
