Security-enhanced high-speed messages transmission based on chaos synchronization system with phase modulation and phase-to-intensity conversion

In this paper, we propose and numerically demonstrate a security-enhanced high-speed chaotic communication system by introducing phase modulation and phase-to-intensity conversion. The driving laser (DL) with delayed optical feedback can be used to generate the chaotic driving signal, which is simultaneously injected into two response lasers (RLs) through a phase modulator (PM) and a dispersion component (De). The simulated results show that, due to the phase modulation and phase-tointensity conversion, TDS of injected chaos signal from DL can be effectively suppressed and its bandwidth can be increased to 39.6 GHz under suitable parameter conditions. Simultaneously injecting the chaos signal into two identical RLs, high-quality chaos signals with weakened TDS and enhanced bandwidth between two RLs can be achieved even under certain parameter mismatches, but the synchronization quality between DL and any one of RLs is extremely bad. Based on the system synchronization, secure transmission of 20 Gbit/s messages can be realized and the transmission distance can be over 200km.