Superluminal and ultraslow light propagation in optomechanical systems

Abstract

We consider an optomechanical double-ended cavity under the action of a coupling laser and a probe laser in an electromagnetically induced transparency configuration. It is shown how the group delay and advance of the probe field can be controlled by the power of the coupling field. In contrast to single-ended cavities, which only allow for superluminal propagation, the possibility of both superluminal and subluminal propagation regimes is found. The magnitudes of the group delay and the advance are calculated to be $\ensuremath{\sim}$1 ms and about $\ensuremath{-}2$ s, respectively, at a very low pumping power of a few microwatts. In addition, the interaction of the optomechanical cavity with a time-dependent probe field is investigated for controlled excitations of mirror vibrations.