Linear and nonlinear experimental regimes of stochastic resonance - art. no. 011101

We investigate the stochastic resonance phenomenon in a physical system bas ed on a tunnel diode. The experimental control parameters are set to allow the control of the frequency and amplitude of the deterministic modulating signal over an interval of values spanning several orders of magnitude. We observe both a regime described by the linear-response theory and the nonli near deviation from it. In the nonlinear regime we detect saturation of the power spectral density of the output signal detected at the frequency of t he modulating signal and a dip in the noise level of the same spectral dens ity. When these effects are observed we detect a phase and frequency synchr onization between the stochastic output and the deterministic input.