Investigations Of Optical Chaos Computing Based On Optically Injected VCSEL

In recent years,chaotic vertical-cavity surface-emitting laser(VCSEL)is widely applied in some fields such as chaotic secure communication,chaotic radar ranging,chaotic photonic reservoir computing,the generation of physical random number and chaotic neural network.Recently,chaotic VCSELs have been generalized to a new field,which is chaos computing.It extends a new way to realize the optical logic path.Compared with the optical computing devices utilizing nonlinear optical effects,the optical chaos computing based on the chaotic VCSEL has many advantages such as more security,flexibility,anti-jamming ability and lower power cost.However,the development of optical chaos computing is still in the initial stage,and the related researches are mainly focused on the realization of basic optical chaos logic operations(such as AND,OR,NOR,etc.),and less attention is paid to optical combinational chaotic logic computing and optical sequential chaotic logic computing.Meanwhile,there are still many key technical problems to be further explored in logic input encoding,threshold judgment mechanism of logic output,reconfigurable characteristics and reliability.Based on these considerations,this project mainly explores the following two aspects:(1)We investigate the evolution of nonlinear dynamic behaviors of two polarization components,as well as the interplay of polarization bistability,frequency detuning and injection strength in the VCSEL with optical injection.By encoding two logic inputs and one clock input in the amplitude of the light from a sampled grating distributed Bragg reflector laser,and by decoding two output logic responses from the two polarization components by the laser,we demonstrate two parallel optical chaotic data-selection computing.The correct logic output response encoded in two polarization components response for 100 ps bit time and the response bit time of the correct logic output encoded in the y polarization component may be 67 ps by the optimization of the injection strength.The probability of the correct response is controlled by the interplay of the bit time,the injection strength and noise strength,and is equal to 1 in a wide region of the injection strength and noise strength.The chaotic data-selection computing in an optically VCSEL offers interesting perspectives for applications where noise is unavoidable and fast switching is required.See chapter 3 for details of this part.(2)We investigate the interplay of injection strength and polarization bistability,as well as the evolution of nonlinear dynamic behaviors of two polarization components in the VCSEL with polarization-preserved optical injection.We explore a new threshold mechanism to judge two logic outputs encoded in different dynamic behaviors of the two polarization components emitted by the VCSEL with polarization-preserved optical injection.We demonstrate implementations of two parallel optical chaotic reset-set(RS)flip-flop operations and two parallel optical chaotic toggle(T)flip-flop operations that are synchronized by a clock signal and response for as short as 1 ns bit time.We further observe the reconfiguration of these two kinds of flip-flop operations with clock synchronization by controlling the duration-time of the reset(toggle)signal with high-level.The probabilities of the correct trigger responses for these two kinds of flip-flop operations are controlled by the interplay of the duration-time of the reset(toggle)signal and the noise strength of the spontaneous emission.The probability that is equal to 1 for the RS flip-flop operations occurs in the long duration-time of the reset(toggle)signal ranging from 480 ps to 592 ps.The probability with 1 for the T flip-flop operations takes place in the short duration-time between 116 ps and 170 ps.Moreover,these two kinds of flip-flop operations are strongly robust to the noise.The optical chaotic flip-flop operation device with clock synchronization and reconfigurable trigger function proposed in our scheme offers interesting perspectives for applications where noise is unavoidable and synchronized multiple triggering is required.See chapter 4 for details of this part.