The Research Of Optical Chaos Secure Communication Based On Integrated Silicon Optical Devices

At present,most of the materials used in laser chaos sources are III-V group materials(such as GaAlAs).However,group III-V compounds present significant barriers to CMOS process compatibility.Silicon photonic devices based on silicon materials have natural advantages in compatibility with CMOS process,which is very conducive to the mass production and low cost of devices,therefore,in recent years,research on silicon-based photonic integration technology in the field of secure communication has become a hot topic.A new scheme of secure communication system using silicon photonic resonator as chaos source is proposed,which theoretically studies the laser chaos generated by silicon photonic microcavity and realizes the design of chaos synchronization in silicon photonic microcavity.Specific work contents include:(1)A unidirectional chaos secure communication system based on silicon photonic devices is proposed: system is composed of two silicon photonic microcavity.Under the condition of appropriate parameter is set,through adjusting the parameters of the external excitation light,silicon microcavity photons produced in the local light field of high strength,through modulation of the carrier absorption,heat and other nonlinear optical effect in the microcavity will produce mechanical oscillation and two-photon absorption effect,and the output of chaos.The laser chaos output in two microcavities is different because of the different initial conditions.The output of one silicon optical microcavity as excitation chaos and is injected into another microcavity to induce the output of response laser chaos,with the injection of excitation chaos and the setting of parameters,the chaos trajectory of the response system gradually tends to the chaos trajectory of the excitation system.Chaos synchronization in two silicon-based photonic microcavities is realized with appropriate injection coefficients,a unidirectional chaos secure communication system is designed based on chaos synchronization between microcavities.The results show that the chaos synchronization with good quality can be achieved in two silicon photonic microcavities,and finally the unidirectional secure communication with a transmission distance of 300 km is realized by setting parameters.(2)A scheme of bidirectional chaos secure communication system based on silicon photonic devices is investigated: the bidirectional communication system is composed of three silicon photonic microcavities.By setting the initial conditions of the three microcavities,the three microcavities will output different laser chaos.By injecting the optical chaos signal excited by the microcavity into the other two response microcavities,the chaos trajectories of the two response microcavities will converge under appropriate conditions,but at the same time,it is still significantly different from the chaos signal excited by microcavities,thus,the high quality chaos synchronization between two response microcavities is obtained,which provides a foundation for the bidirectional loading and transmission of subsequent communication signals.Through numerical simulation analysis,the bidirectional long distance information transmission and demodulation of 100 km can be realized.