Experimental Observation of Vibrational Resonance
This chapter focuses on the experimental observation of vibrational resonance. One of the first examples where vibrational resonance was experimentally observed was in Baltanas et al. . The authors considered an analog simulation of the overdamped Duffing oscillator with two stable equilibrium states and one unstable equilibrium state. The system is driven by a biharmonic force. A resonant-like behaviour was realized when the amplitude or the frequency of the high-frequency component was varied. The experimental result was confirmed by the numerical simulation. Later, Ullner et al.  reported the occurrence of vibrational resonance in an excitable electronic circuit. Also Chizhevsky and his collaborators [3, 4] presented an experimental observation of vibrational resonance in a vertical cavity surface emitting laser. This device is capable of displaying a bistability of polarization states of the emitted field that can be monitored by the applied injection current. It has been shown that observed resonance can be used for the detection of low-level noisy signals. Occurrence of stochastic resonance in this system was also reported [5, 6]. In nonlinear circuit analysis, the bistable Chua’s circuit is commonly used as a prototype circuit to investigate a variety of dynamics. Experimental evidences for vibrational resonance in a single Chua’s circuit and enhanced signal transmission in a system of unidirectionally coupled n Chua’s circuits driven by a biharmonic signal were reported .