We experimentally demonstrate phenomenon of stochastic-resonance in optical bistability from an optical ring cavity containing three-level (Λ-type) rubidium atoms. The measured results match qualitatively with theoretical predictions of the generic model for the SR phenomenon.
Stochastic resonance (SR) is experimentally demonstrated in an atomic optical bistable system consisting of three-level atoms in $\ensuremath{\Lambda}$-type configuration confined in an optical ring cavity. The optical bistable system with enhanced Kerr nonlinearity due to atomic coherence is driven by a periodic signal and a Gaussian white noise source with variable amplitude, and displays an improved output signal-to-noise ratio, a characteristic signature of SR. The measured results match qualitatively with the theoretical predictions of the generic model for the SR phenomenon.