1 research outputs found
Radiatively Broadened Incandescent Sources
We study the incandescence of a semiconductor
system characterized
by a radiatively broadened material excitation. We show that the shape
of the emission spectrum and the peak emissivity value are determined
by the ratio between radiative and nonradiative relaxation rates of
the material mode. Our system is a heavily doped quantum well, exhibiting
a collective bright electronic excitation in the mid-infrared. The
spontaneous emission rate of this collective mode strongly depends
on the emission direction and, uncommonly for an intersubband system,
can dominate nonradiative scattering processes. Consequently the incandescence
spectrum undergoes strong modifications when the detection angle is
varied. Incandescence is modeled solving quantum Langevin equations,
including a microscopic description of the collective excitations,
decaying into electronic and photonic baths. We demonstrate that the
emissivity reaches unity value for a well-defined direction and presents
an angular radiative pattern that is very different from that of an
oscillating dipole