Stochastic resonance in a tristable optomechanical system

In this work we theoretically investigate the stochastic resonance (SR) effect in an optomechanical membrane system subject to two weak signals (one optical field and one mechanical force). The quadratic optomechanical coupling allows us to find a region with tristability where the noise-activated stochastic switching among three stable states occurs and SR phenomena are observed at the cooperation of input signals and noise. We show that the mechanical force and the optical field respectively serve as an additive signal and a multiplicative signal to the membrane position, and they induce completely different SR behaviors. Moreover, when two signals coexist the SR effect can be enhanced, and the beating effect appears in the SR synchronization process with unsynchronized signals.