A novel regime for the dynamical Casimir effect

The dynamical Casimir effect (DCE) is the production of photons by the amplification of vacuum fluctuations. In this paper we demonstrate new 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 linear stability analysis and investigate the dynamic stability of the system under small fluctuations. By using a numerical solution of the Heisenberg equations of motion, the time evolution of the number of photons produced in the unstable region is studied.