Critical slowing down in a bistable model with squeezed vacuum environment

Critical slowing down effect in a bistable model of a two-level atomic medium in a ring cavity and in contact with squeezed vacuum field is examined within the mean field approximations in the high-, low- and arbitrary-Q cavity cases. Depending on the squeezed vacuum field phase parameter, the time response to linear perturbation of the incident field near the swtiching-on point can be enhanced or reduced compared with the normal vacuum case. In the low-Q cavity case with atomic collisional broadening switching time is both increased and become insensitive to the phase of the squeezed vacuum field. Analytical expressions are given and analysed for the critical (extermal) values of the incident field. In the high-Q cavity, Gaussian field feature causes lesser-steep transition between the stable states in both the normal and squeezed vacuum cases.Received: 25 April 2004, Published online: 24 August 2004PACS: 42.65.Pc Optical bistability, multistability, and switching, including local field effects - 42.65.-k Nonlinear optics