  We establish an important connection between coherent quantum feedback and
the Ornstein-Uhlenbeck process in quantum optics. We show that an emitter with
fluctuating energy levels in front of a mirror results in an Ornstein-Uhlenbeck
process for electronic populations, although the fluctuation of the energy
levels is assumed to be uncorrelated in time and space. Based on a Heisenberg
equation of motion description of the quantum feedback dynamics, we discuss
additionally the impact of phase noise on the population dynamics and provide
examples in which noise itself is not detrimental but supports and enhances
typical features of quantum feedback such as self-stabilization.
