Stochastic resonance in bistable systems

Abstract

The stochastic Resonance (also known as SR) a phenomenon in which the signal and the signal to noise ratio of a non linear device is maximized for a moderate value of noise intensity.It often occurs in bistable and excitable systems with subthreshold inputs.For lower noise intensities,the signal does not cause the device to cross threshold so little signal is passed through it.For large noise intensities,the output is domonated by the noise,also leading ,also leading to a low signal to noise ratio. For moderate intensities,the noise allows the signal to reach threshold ,but the noise intensity is not so large as to swamp it.Thus,a plot of signal to noise ratio as a function of noise intensity shows an upside down 'U" shape.Theoretical ideas explaining and describing SR are discussed.Some revealing experimental data that places SR within the wider context of statistical physics has been reviewed and established.