Research On Logic Gate Based On Optical Modulator And Its Application In Physical Layer Encryption

With the rapid increase of Internet services and the rapid growth of network data traffic,the optical communication system,as the main data carrier,has been developing to afford a much higher transmission rate,and the optical communication network has become increasingly complex.The improvement of transmission rate puts forward higher requirements for the signal processing ability of optical network nodes.However,due to the imperfection of optical signal processing technology,some signal processing in network nodes still need to convert optical signals into electrical signals,and then convert electrical signals into optical signals after the completion of electrical domain processing.The conversion of Optical-Electric-Optical reduces the processing efficiency,seriously,the processing capacity of network nodes will seriously restrict the development of optical communication in the future,with the electronic technology approaching its physical limit.Therefore,the research of optical signal processor technology is still one of the hot topics in the field of optical communication.In addition,optical signal processing can achieve parallel operation and is not sensitive to electromagnetic interference and electrical short circuit,so it is widely used in optical computing,optical instruments,optical networks and other fields.Similar to the electronic digital signal processing technology,the optical logic gate is the basic unit of the optical signal processing technology and the basis for many applications.For example,the optical Boolean XOR gate is the core device in the decision and comparison circuit,which can realize address recognition,packet conversion,label exchange,bit sequence parity,packet synchronization,address comparison,data encryption/decryption,binary addition,Pseudo-random binary sequence generation and pattern recognition,etc.Therefore,the research of optical logic gate is of great significance for improving optical signal processing technology and promoting the development of all-optical network.This paper focuses on the realization and application of optical logic gate.An optical logic operation conversion scheme based on modulator is proposed;the design scheme of optical logic gate with three input,optical path selector based on MZM and optical signal serial/parallel converter are proposed;the optical logic gate based on I/Q modulator is applied to the secure communication system.According to the actual demand,a scheme design of secure communication system based on optical logic gate is proposed.The specific research contents are as follows:(1)In this paper,the implementation scheme of optical logic gate based on I/Q modulator is studied comprehensively,and its parameters are optimized.The conversion scheme of optical logic gate based on I/Q modulator and the design scheme of optical logic gate with three inputs are proposed,which are verified by simulation.(2)The design scheme of optical path selector and optical signal serial/parallel converter based on MZM is proposed and verified by system simulation software.(3)The optical logic gate based on I/Q modulator is applied to the secure communication system.The physical layer encryption scheme based on the optical logic gate is designed.The experiment realizes the encryption of the signal with the speed of 10 Gbit/s and the transmission of the encrypted signal for 50km.