Theoretical Investigations On The Chaos Synchronization And The Modulation Response Performances Of F-P Semiconductor Laser

Along with the rapid development of moden communizcation technology,new generation of security information transmission has become more and more important.In recent years, chaos and chaos synchronization of semiconductor lasers(SLs) has attracted much attention for its potential applications in secure communications.However,at present,the researching targets are mainly focused on the same types of SLs,the synchronization systems composed of different types of SLs are nearly not being widely researched and the deep physical insight into chaos and chaos synchronization are lacking.In this paper,chaos and chaos synchronization between multimode semiconductor laser and single-mode semiconductor laser are studied theoretically, and the modulation response performances of F-P semiconductor laser(FP-LD) subjected to light injection from another FP-LD are also being theoretically investigated.The main works of this dissertation are listed as follows:Firstly,reviewed the researching progrosses about lasers' chaos synchronization and modulation response of FP-LD within the past ten years,and then simulated the chaotic dynamic characteristics of mutimode SL subject to external all-optical feedback and analyzed the chaotic features of mutimode SL'modes with in-phase and anti-phase correlation properties among these modes(five longitudinal modes are discussed for FP-LD in this dissertation).For the system composed of a multimode emitted laser diode and a single-mode received laser in an open-loop configuration,chaos synchronization performance has been investigated numerically under different optical injection patterns.The results show that generalized synchronization can be achieved in this system,but optical injection patterns and parameter mismatches have great effects on the synchronization performance;depending on the optical spectrums of the received laser,the physical mechanism of chaos synchronization deterioration for multi modes injection (MMI) compared to single mode injection(SMI) is given.Further,with optical mutually coupled injection,the system's dynamic characteristics and synchronization performance are also been discussed.Though two subsystems are composed by multimode SL and a single-mode SL separately,generalized synchronization and localized synchronization(SLs are operating under periodic oscillations) can be achieved in different conditions.With central mode(m=0) injected, all the side-modes of FP-LD are restrained,but the two SLs have the same bifurcation path to chaos.And further theoretical researching results show that,generalized synchronization can be easily achieved when the synchronization systerm is under long time-delay mutually injection condition.Finally,for the system composed of one FP-LD and two DFB-LDs,which are located in a line of time-delayed mutually coupled condition with no direct communication between the DFB-LDs,complete synchronization with no time-delays and generalized synchronization can both be easily obtained.For generalized synchronization,the synchronization coefficients is as high as 0.98,even the two mutual injection time-delays are different to each other.No matter the mutually coupled synchronization system is symmetry or not,the Full-Width Half-Maximum (FWHM) cofficients of the cross-coreelation function can be sharply reduced to 0.022ns,which is superior to some other reports about chaos radar.For this synchronization system with three lasers mutually coupled,the synchronization performances with parameters mismatching±10% are also checked.Finally,the last work we have done in this dissertation is about the modulation response characteristics of a Fabry-Perot semiconductor laser(slave FP-LD) subjected to light injection from master FP-LD.The results show that the modulation response performances of the slave FP-LD depend on the light injection strength,the central mode frequency detuning△f and the mode spacing difference△λbetween the slave FP-LD and the master FP-LD.For the parameter values well selected,the 3dB modulation bandwidth can increase 5.5 times compared with the case of free running,which is 28GHz in my theoretical simulation results.