  The optomechanics can generate fantastic effects of optics due to appropriate
mechanical control. Here we theoretically study effects of slow and fast lights
in a single-sided optomechanical cavity with an external force. The
force-induced transparency of slow/fast light and the force-dependent
conversion between the slow and fast lights are resulted from effects of the
rotating-wave approximation (RWA) and the anti-RWA, which can be controlled by
properly modifying the effective cavity frequency due to the external force.
These force-induced phenomena can be applied to control of the light group
velocity and detection of the force variation, which are feasible using current
laboratory techniques.
