Design and Simulation of the All-Optical Chaotic System over Free-Space Optical Communication Link under Different Weather Conditions

To solve data security concerns, semiconductor laser chaos generation is currently being used to increase data security and prevent data theft during its transmission from the transmitter to receivers. Chaotic lasers are extensively employed in secure communication, where optical chaotic communication is a hopeful technique for improving the privacy and security of communications networks. Our proposed method, which uses the double-delay feedback mechanism to generate the optical chaotic signal, hides the information within the chaos in this type of secure communication system. Chaotic data a mix of incoming signals and optical chaotic, is sent via Free-space optical (FSO). The different channel lengths of data transfer are implemented for communication and under various weather conditions such as ideal conditions, fog, and rain. Synchronization between the sending and receiving sides is achieved by adjusting the parameters on both sides. By subtracting the chaos from the sent signal on the receiving side, the received signal can be returned to its initial state. It is possible to assess the method by obtaining Q-factors and bit error rates (BERs), which can then be used to determine the quality of the received signal. Based on our comparison of Q-factors and BER values for channels of various lengths and different weather conditions, the increase of the FSO channel length caused a link distance degradation at all weather conditions. In addition, the fog and rain caused attenuation and scattering of the light signal increasing the bit error rate (BER) and a decrease in the Q-factor.