EN
A detailed stability analysis is performed for a highly excited semiconductor modelled as an exciton-electron-hole-photon system driven externally by optical pumping. Chaotic self-pulsations are shown to occur on both the upper and lower branches of the bistable steady state curve of the system via a sequence of period-doubling oscillation process. Such a route to chaos is well known in laser physics and in other nonlinear systems but not in highly excited semiconductors yet.