| All-optical flip-flop is a basic optical storage cell device.As an optical device with multi-states steady output,all-optical flip-flop has a storage capacity of one or more bits.Also as the basic unit of memory optical device,flip-flop can be applied to data recovery,format conversion,frame header processing and so on.All-optical flip-flops are key components of optical packet switching and routing,all optical flip-flop and all-optical logic gates and other basic devices can realize optical signal processing comprehensively,All-optical flip-flop,all-optical logic gates and other optical devices may achieve a optical signal processing completely,all-optical flip-flops will become the key factor to realize the high speed network.A novel all-optical flip-flop based on passive micro Sagnac waveguide ring which greatly facilitates easily cascade is presented in this thesis.The AOFF adopts highly nonlinear of hollow-core photonic crystal fiber(HC-PCF).Thus it not only can decrease the length of circuit,the input power and the transmission loss,but also improve the coupling efficiency.The structure is based on polarization Sagnac switch,and controls output optical power whose feedback configuration can memory output signal states,thereby all-optical synchronous D-type,S-R-type,T-type and J-K-type flip-flop operation has been realized,this kind of all-optical flip-flop has the characteristics of small volume,high transmission rate,low power consumption and stable performance.This project was supported by NSFC “Research on physical layer security and optical co ding for free space optical communication(61671306)”,and JCYJ “Research on key technolo gies of optical communication based on optical encoding physical layer security(20160328145357990)”.In this thesis,the theory of light field from the Maxwell equation of the electromagnetic wave to the wave equation is first analyzed,and then the principle of the traditional Sagnac interferometer and its nonlinear response characteristics are introduced in detail,the minimum threshold power of the switch is deduced from the mathematical transmission matrix of the coupler and the orthogonal transmission of polarized light in the fiber.It deduced the threshold power can be reduced to the power level of m W and the digital simplification model of such a switch can be achieved.The principle and design of waveguide full-function flip-flop(D-type,SR type,JK type and T-type flip-flop)are analyzed in detail.FDTD(time domain finite difference method)is used as a research tool to simulate the design principle and light transmission characteristics,and the experiment is carried at the rate of 100 Gb/ s in system of Optisystem 8.0.In this thesis,the problems in the simulation results are discussed,the narrowing of the output waveform and the residual problem of the base are studied.The improvement method is proposed and the error rate of the system is analyzed.The length and nonlinear coefficient of the photonic crystal fiber and the gain of the amplifier are optimized on the bit error rate.The results show that the transmission rate is up to 100 Gb/ s,the input power is 0.05 m W,the response time is in the order of ps,the bit error rate is 10-9,and the little volume is suitable for integrate. |
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