Quadrature squeezing of a higher-order sideband spectrum in cavity optomechanics.

We propose an efficient scheme to generate quadrature squeezing of a higher-order sideband spectrum in an optomechanical system. This is achieved by exploiting a well-established optomechanical circumstance, where a second-order nonlinearity is embedded into the optomechanical cavity driven by a strong control field and a weak probe pulse. Using experimentally achievable parameters, we demonstrate that the second-order nonlinearity intensity and the frequency detuning of a control field allow us to modify the amplitude of higher-order sidebands and improve the amount of squeezing of a higher-order sideband spectrum. Furthermore, in the presence of a strong second-order nonlinearity, an optimizing quadrature squeezing of a higher-order sideband spectrum can be achieved, which provides a practical opportunity to design the squeezed frequency combs and other precision measurements.