Investigating the impact of correlated white noises on the bistability behavior in an optical three-level bistable system

Abstract

The effect of correlated white noises on the optical bistability behavior of three-level atomic systems is theoretically investigated. Noise-induced bistability is demonstrated in an atomic optical bistable system consisting of three-level atoms in Λ-type configurations confined in an optical ring cavity. The output field as a result of enhanced Kerr nonlinearity induced by atomic coherence in the electromagnetically induced transparency system is variable due to the noises in laser parameters and the cooperativity parameter. Therefore, noise is mainly responsible for such induced bistability in the system. It is found that with the cross-correlation noises, the hysteresis loop of optical bistability can be clearly expanded in comparison with the deterministic case and the atomic system could show multistability behavior. This is specifically considerable for positive cross-correlated noises where it could expand the domain of the hysteresis loop. In the presented atomic system the numerical result shows that noise can induce bistability in the absence of spontaneously generated coherence. Furthermore, it is salient that the noise could induce bistability when the system is below its deterministic threshold for bistability.