HIGH-FREQUENCY STOCHASTIC RESONANCE IN PERIODICALLY DRIVEN SYSTEMS

High frequency stochastic resonance (SR) phenomena, associated with fl uctuational transitions between coexisting periodic attractors, have b een investigated experimentally in an electronic model of a single-wel l Duffing oscillator which is bistable in a nearly resonant field of f requency omega(F). It is shown that, with increasing noise intensity, the signal-to-noise ratio (SNR) for a signal due to a weak trial force of frequency OMEGA approximately omega(F) at first decreases, then in creases, and finally decreases again at higher noise intensities: The behavior is similar to that observed previously for conventional (low- frequency) SR in systems with static bistable potentials. The stochast ic enhancement of the SNR of an additional signal at the mirror-reflec ted frequency \OMEGA-2omega(F)\ has also been observed, in accordance with theoretical predictions. Relationships with phenomena in nonlinea r optics are discussed.