Auxiliary cavity enhanced mode splitting and ground-state cooling of mechanical resonator in hybrid optomechanical system

We theoretically demonstrate the mode splitting and the ground-state cooling of optomechanical resonator in a hybrid optomechanical system, where one optomechanical cavity with high cavity dissipation is coupled to an auxiliary optical cavity with high quality factor. The fluctuation spectrum of the resonator presents the behavior of mode splitting with controlling the parameters, such as the cavity-pump-field detuning, the cavity-cavity coupling strength J, the pump power P, and the decay rate ratio delta of the two cavities. In addition, the resonator can also reach the ground-state cooling under different parametric regimes. Our study may provide a further insight into cooling macroscopic objects in a hybrid optomechanical systems.