Enhancement of Upper Second-Order Sidebands Based on Optomechanically Induced Absorption in a Double-Cavity Optomechanical System

We propose an effective scheme to enhance the efficiency of optical second-order sideband (OSS) via optomechanically induced absorption (OMIA) in a double-cavity optomechanical system. In this double-cavity optomechanical configuration, the optomechanical cavity is driven by a strong control field and a weak probe pulse, while the assisted cavity is excited by another strong control field. Using experimentally achievable parameters, we identify that the present optomechanical system can create the OMIA effect and improve the efficiency of the upper OSS beyond that is achieved by employing optomechanically induced transparency (OMIT). With the aid of OMIA, we also report that the maximum efficiency and linewidth of the upper OSS peak can be modulated by the double-cavity coupling strength and the detuning of the driving field. The present proposal offers a new path to optimize optical nonlinearity and design chip-scale signal processing.