The dynamical Casimir effect (DCE) is the production of photons by the amplification of vacuum fluctuations. In this paper, we demonstrate resonance conditions in DCE that potentially allow the production of optical photons when the mechanical frequency is smaller than the lowest frequency of the cavity field. We consider a cavity with one mirror fixed and the other allowed to oscillate. In order to identify the region where production of photons takes place, we do a stability analysis of the Heisenberg–Langevin equations of motion and investigate the dynamic stability of the system under small fluctuations. By using a numerical solution of the master equation, the time evolution of the mean number of photons produced in the unstable region is studied.

• Received 3 July 2019

DOI:https://doi.org/10.1103/PhysRevA.100.033815