Quantum theory of optomechanical cooling

We review the quantum theory of cooling of a mechanical oscillator subject to the radiation pressure force due to light circulating inside a driven optical cavity. Such optomechanical setups have been used recently in a series of experiments by various groups to cool mechanical oscillators (such as cantilevers) by factors reaching 105, and they may soon go to the ground state of mechanical motion. We emphasize the importance of the sideband-resolved regime for ground state cooling, where the cavity ring-down rate is smaller than the mechanical frequency. Moreover, we illustrate the strong coupling regime, where the cooling rate exceeds the cavity ring-down rate and where the driven cavity resonance and the mechanical oscillation hybridize.