TORI AND THEIR BIFURCATIONS IN AN OPTICALLY INJECTED SEMICONDUCTOR-LASER

We show that there is motion on a torus in the single-mode rate equati ons of a diode laser subject to weak optical injection. It occurs in t he transition from relaxation oscillations to unlocked dynamics and co rresponds to a relaxation oscillation whose amplitude is modulated. Th e stability of the torus depends on the linewidth-enhancement factor a . The case of an unstable torus gives rise to bistability, resulting i n hysteresis when the detuning of the input signal is varied for suita ble injection strength. We present the relevant dynamics by several pa nels, including phase plots, the time series of the power, and the fie ld spectrum. (C) 1998 Elsevier Science B.V. All rights reserved.