Time Evolution of an Optically Bistable System- Local Relaxation and Tunneling

After a brief review of some known steady state properties of an absorptive bistable system, we discuss in some details new aspects of the transient response that follows a sudden perturbation from steady state. The evolution of the perturbed bistable system towards its new steady state consists of two generally distinct phases: one is the local relaxation within each well of the bimodal potential, the second is the tunneling through the local maximum that separates the metastable and stable steady states. We give an analytic description of both phases of the evolution, and give explicit formulas for the local and global relaxation rates.