Abstract

Excitability has long been studied as an important class of dynamical phenomena in biological and chemical systems. Excitability underlies wave propagation and formations, such as cardiac muscle and nerve wave front and spirals under the FitzHugh-Nagumo model and chemical excitation waves in Belousov-Zhabotinsky reaction. However, it is only recently that excitable features have been revealed in other nonlinear systems that have different physical mechanisms from the biological and chemical interactions, such as in liquid crystals and most recently in lasers. In this paper, we show an optical bistable device to be excitable. We derive a model description for such a device and establish that its excitable behaviour originates from saturation effect of the input and output electric fields coupled with the absorption-induced Kerr type nonlinearity in the medium in two different time scales.

© 1998 IEEE