Abstract

Semiconductor lasers are typical class-B lasers in which the decay rates obey γ_p, γ ≪ γ , where γ_p, γ . and γ are the decay rates of the photons, population inversion and polarization, respectively. Therefore an isolated semiconductor laser is well described by rate equations with only two independent variables (photon number and carrier population) so that chaos is not observed. Here we show two different geometries to make chaos feasible in a semiconductor laser system. The results clearly demanstrate the origin of instability in the semiconductor laser: the interaction in the nonlinear laser medium between undamped relaxation oscillation (which expresses the energy exchange between carrier population and photons) and some external modulation (which may include optical feedback).

© 1992 Optical Society of America