Delayed interference-based broadband optical chaos generation in a mutual coupled RSOA and DFB system

In this Letter, a delayed interference (DI)-based chaos generation scheme in a mutually coupled system consisting of a reflective semiconductor optical amplifier (RSOA) and a distributed feedback (DFB) semiconductor laser is proposed. We experimentally demonstrate its capability of generating broadband chaos with a large effective bandwidth and a flat power spectrum, and the influences of relevant parameters on the system performance are thoroughly analyzed. Compared to the conventional optical feedback-based chaos generation schemes, the proposed system can simultaneously output two chaotic signals with enhanced bandwidth and high spectral flatness. Moreover, the time-delay signature (TDS) of chaotic signals generated by this configuration is also effectively suppressed.