Research On Long-haul Chaos Synchronization Mechanism Of Semiconductor Lasers Driven By A Common Signal

This paper numerically studies the long-haul chaos synchronization scheme of semiconductor lasers driven by a common signal based on hybrid amplification relay and periodic dispersion compensation.The co-drive chaos synchronization system can achieve high synchronization between the response lasers,and at the same time,the correlation between the output of the driving laser and the response laser is very low,which improves the security of the system.Therefore,the application comparison in the field of chaotic secure communication and key distribution widely.Chaotic optical communication is compatible with modern optical fiber technology.By adding optical fiber links to the co-drive chaos synchronization system,safe and long-distance chaotic optical communication can be realized,but the loss,dispersion and nonlinear effects in the link will also be large.The signal quality is reduced to a certain degree,which is not conducive to system synchronization.Therefore,the key to achieve long-distance co-drive chaos synchronization is to compensate for fiber link damage.In recent years,long-distance chaotic secure communication and key distribution have been extensively studied.The dispersion compensation of the link usually uses dispersion compensation fiber(DCF),and uses erbium-doped fiber amplifier(EDFA)to compensate for power loss to realize 100-kilometer metropolitan area network fiber transmission.The dispersion compensation efficiency of DCF,the spontaneous emission(ASE)noise introduced by EDFA,and the nonlinear effect are the key factors that limit the transmission distance to 1000 kilometers of the intercity network.Therefore,reducing the ASE noise and suppressing the influence of fiber nonlinearity are of great significance for realizing the chaos synchronization of the intercity network.In this paper,optical feedback distributed feedback(DFB)semiconductor laser is used as the driving source,standard single-mode fiber(SMF)is used as the chaotic signal transmission medium,and two optical feedback DFB lasers are used as response lasers to construct a long-distance co-drive chaos synchronization system.In terms of transmission performance,the following two researches have been mainly carried out:1.EDFA relay and periodic dispersion compensation are used to compensate for fiber link damage.In the simulation,by optimizing the fiber input optical power and the span of single-span,the influence of nonlinear effects is reduced,and the distance limit of the EDFA-relayed chaos synchronization scheme of semiconductor lasers driven by a common signal is explored.2.The research found that the distributed fiber Raman amplifier has the advantage of low noise.The hybrid amplifier with EDFA can achieve high gain and low noise amplification.Therefore,we switch to FRA+EDFA hybrid amplification to reduce the impact of ASE noise.Adjusting the gain ratio of the two amplifiers verifies the feasibility of co-driving chaotic synchronization over a thousand kilometers.This study provides a reference for the realization of a thousand kilometers co-driving optical fiber chaos synchronization,which can be applied to the chaotic secure communication of the intercity network and the key distribution.