Complex and broadband characteristics of semiconductor ring lasers with optical feedback

We numerically investigate the complex and the broadband characteristics of semiconductor ring laser (SRL) with optical feedback. The results show that the SRL with optical feedback is brought into chaotic behaviors with proper parameters and the dynamic behavior of which is complex. The bifurcation diagrams of chaos generation processes and detailed states with different parameters are demonstrated. The bandwidth of the chaos is also studied in this paper and the widest bandwidth is about 18 GHz when the feedback coefficient is 0.5 which is wider than the traditional edge-emitting lasers with optical feedback.