Study On Stochastic Resonance Of Opto-Mechanical Systems

For a long time,it has been a research hotspot in many application fields to extract useful signals or detect weak signals from strong noise background.Traditional weak signal detection is mainly based on reducing noise and extracting useful signals.With the development of nonlinear dynamics,a new weak signal detection method,stochastic resonance method,has emerged.Different from the traditional detection method,stochastic resonance transforms the part of noise energy into signal energy through a nonlinear system to enhance the weak signal and improves the signal-to-noise ratio of the system.Stochastic resonance provides an effective way for weak signal detection,which is of great significance in theory and application.In this paper,we study the stochastic resonance in a typical nonlinear system,the opto-mechanical systems,in a semiclassical frame.Firstly,we discuss the stochastic resonance in a standard single cavity optical mechanical system.We deduce the dynamic equation of the system theoretically and analyze the stability of the system.For the bistable region of the system,the dynamic behavior of the system driven by the sub-threshold weak light signal and the weak periodic force is discussed.When a sub-threshold weak signal or two signals act on the system together,inputting a noise with proper strength can enhance the weak signal to promote the periodic transition of the mechanical oscillator between the two potential wells and produce the phenomenon of stochastic resonance.At the same time,when two signals act on the system together,coherent superposition can be produced.For two signals of the same frequency,the existence of phase difference can lead to the cancellation of partial coherence or even complete destructive coherence,and the phenomenon of stochastic resonance of the system can be weaken or even disappeared.If there is a small frequency difference between the two signals,the coherent superposition will cause the beat effect,the phase difference will only cause the overall translation of the system output,and the stochastic resonance effect of the system will also produce the interesting beating-like phenomenon.Secondly,we consider the single cavity opto-mechanical system coupled with the other vacuum cavity,which form double-cavity opto-mechanical system.Then,we study the stochastic resonance in the double-cavity system.Under the same system parameters,the two-cavity system has the same bistability property and bistable region as the single cavity system.Meanwhile,we analyze the steady-state resident time distribution of the system and determine the signal frequency matching the system.With the aid of appropriate amount of noise,the double cavity system can not only realize the stochastic resonance phenomenon caused by sub-threshold weaksignal or weak periodic force,but also realize the stochastic resonance phenomenon and the beating-like phenomenon excited by the interaction of two signals.However,compared with the single cavity system,a cavity-cavity coupling channel has been added in the double-cavity system,which makes the threshold value of weak signals required for the system to generate stochastic resonance phenomenon greatly reduced,at least 50%,which is more conducive to weak signal detection and processing.