Secure communication using chaotic synchronization in mutually coupled semiconductor lasers

In this paper, we propose a scheme of the secure communication systems, in the frame of the chaotic synchronization of two semiconductor lasers with optical feedback in mutually coupled configuration within the new modified rate equation of lasers by using the numerical simulations. We explore the robustness of this synchronization scheme with parameter mismatches. A high sensitivity of the synchronization of the lasers via the new control parameter mismatch is discussed in the temporal and frequency domains. Moreover, a possible complete synchronization with negative time lag is discussed. As a result, this leads the receiver to be in the future state of the transmitter. To sustain this proposed scheme, we present the encrypted transmission of binary messages at a bit rate of 250 Mbits/s, and we show that the digital messages at the output receiver laser are perfectly recovered using a finite impulse response filter. The error bits, the error rates as well as the effects of parameter mismatches on the recovered messages are evaluated.