Chaos Synchronization Communication Based on Dual-Path Mutual Coupling Semiconductor Lasers

We build a chaos synchronization communication system with less environmental impact and better stability, using the dual-path mutual coupling semiconductor laser as a transmitter of chaotic light. The communication capability of this system is studied from the hiding of time delay characteristics, the correlation between the transmitting and receiving lasers, and the output chaotic optical bandwidth. The peaks of the feedback time delay characteristics of the external cavity of this system, the peaks of the mutual information function of the transmitting and receiving lasers, and the output chaotic optical bandwidth of the system arc calculated by using mathematical tools such as autocorrelation function and mutual information function. The peak value of feedback time delay characteristic of the dual-path mutual coupling system can be reduced to 0.1899 when the transmitting and receiving lasers arc synchronized by adjusting the parameters, which is 0.1696 lower than the characteristic peak value of a single-path mutual coupling system under the same conditions. The maximum cross correlation coefficient between receiving and transmitting lasers is 0.9113. In addition, the central frequency detuning up to 21 GHz can broaden the output optical bandwidth to 3.319 GHz. The experiment verifies that the chaotic carrier generated by the dual-path mutual coupling system can hide the sinusoidal signal well and successfully demodulate at the receiver.