DETAILED ANALYSIS OF COHERENCE COLLAPSE IN SEMICONDUCTOR-LASERS

Experimental and theoretical studies of coherence collapse in GaAs/AlG aAs laser diodes with weak optical feedback show two distinct routes t o chaos. In each case we observe undamped relaxation oscillations, the n external cavity mode beating, and finally coherence collapse. When t here is frequency locking between the relaxation oscillations and exte rnal cavity modes, a period doubling sequence is followed, otherwise t he route to chaos is via quasiperiodicity.