  In his celebrated 1916-17 papers in which he proposed the A and B
coefficients for the spontaneous and stimulated emission of energy quanta from
excited atoms, Einstein conjectured that stimulated emission involves the
release of individual quanta (later dubbed "photons") along the direction of an
incident photon with the same energy, momentum, phase, and polarization state
as that of the incident photon. According to classical electrodynamics, of
course, an oscillating dipole must radiate an azimuthally symmetric
electromagnetic field around its axis of oscillation. Nevertheless, Einstein
suggested that the release of stored energy from excited atoms in the form of
discrete quanta (photons) must be directional, and that, in the case of
stimulated emission, the direction of the emitted photon must coincide with
that of the incident photon. The goal of the present paper is to show that some
of the prominent features of absorption and stimulated emission emerge from
Maxwellian electrodynamics in conjunction with the simple mass-and-spring model
of an atom known as the Lorentz oscillator model.
