Bidirectional Long-Distance Chaotic Secure Communication System Based On Neural Network Algorithm And Dual Optical Feedback Semiconductor Laser

Information security as a national strategy has been to focus on.Optical chaotic secure communication is to load information into a chaotic carrier generated by a nonlinear device such as a semiconductor laser for secure transmission,thereby realizing data encryption at the physical layer.At present,the research of optical chaotic secure communication based on semiconductor lasers mainly focuses on the security,transmission distance and transmission rate of the system.In particular,the rise of artificial intelligence technology has greatly promoted the development of various fields of national production.Obviously,the organic combination of artificial intelligence technology and optical chaotic secure communication technology to achieve high-speed,long-distance,and security-enhanced information secure transmission has great scientific research and application value.This paper introduces the performance of a chaotic secure communication system based on a drive-response distributed feedback semiconductor laser(DFB-SL).Under this system structure,response to the increase of the injection intensity of the laser can effectively improve the synchronization quality between the two lasers,but due to the influence of the internal noise of the laser,the synchronization coefficient cannot reach 1.In addition,the increase of the signal transmission rate will deteriorate the decoding quality of the system,and the structure is very easy to be cracked from the aspect of security.On this basis,we further proposed a two-way long-distance chaotic synchronization communication system based on neural network algorithms(NN)and double optical feedback(DOF)SL and studied the digital image transmission and recognition of the system performance.The research results show that the time delay signature(TDS)of the chaotic signal output by the driving laser(DL)with DOF is greatly weakened.The low-latency chaotic signal is symmetrically injected into the two response lasers.Under appropriate injection conditions,the bandwidth of the chaotic carrier signal is further increased,and the TDS are further suppressed.High-quality chaotic synchronization can be achieved between the responding lasers(RLs),and the synchronization quality between the DL and any RLs is extremely poor.Two chaotic signals output by the RLs are used as carrier waves,and the information is encrypted by means of chaotic burying.The single-mode fiber channel is used as the transmission channel,and the 10Gbit/s message signal is transmitted within140 km in the channel,and the Q-factor of the decoded signal can still be maintained at around 6.In a traditional communication system,when the Q-factor is lower than 6,it is considered that the system will not be able to continue to transmit information.The NN is used to identify the transmitted and decoded digital image information.After the transmission distance is increased to 220 km,although the Q-factor at this time is less than1,the accuracy rate can be maintained above 90%.Therefore,after applying the NN to the two-way communication system,the transmission distance of the system is increased from 140 km to 220 km.