Wideband Time Delay Signature-Suppressed Chaos Generation Using Self-Phase-Modulated Feedback Semiconductor Laser Cascaded With Dispersive Component

We propose a wideband chaos generation scheme that shows significant bandwidth enhancement and excellent time delay signature (TDS) suppression, by introducing self-phase modulation in the feedback loop of external-cavity semiconductor laser (ECSL) and passing the ECSL-generated chaos through a dispersive component. Proof-of-concept experiment and thorough complementary numerical simulations are carried out to study the efficient bandwidth and TDS characteristics of the generated chaos. The results demonstrate that with the joint contributions of self-phase modulation and dispersion, the efficient bandwidth of chaos can be enhanced by several times and the spectrum gets much flatter. Simultaneously, the TDS can be completely suppressed, in a wide operation parameter range. The proposed wideband chaos generation scheme shows great potential for the applications of fast random bit generation, high-resolution chaotic radar, and high-speed chaos communication.